UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

U.S. Silica Holdings, Inc.

(Name of Registrant as Specified in its Charter)

(Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)

Payment of Filing Fee (Check the appropriate box)

PRELIMINARY PROXY STATEMENT — SUBJECT TO COMPLETION, DATED MAY 24, 2024

U.S. SILICA HOLDINGS, INC.

24275 Katy Freeway, Suite 600

Katy, TX 77494 

   , 2024

Dear Fellow Stockholder:

We invite you to attend a special meeting (we refer to such meeting, including any adjournment or postponement thereof, as the “Special Meeting”) of the stockholders of U.S. Silica Holdings, Inc. (“U.S. Silica” or the “Company”), to be held virtually via live webcast on      , 2024 at       , Central Time. You will be able to virtually attend and vote at the Special Meeting by visiting   . Please note that you will not be able to attend the Special Meeting physically in person. For purposes of attendance at the Special Meeting, all references in the accompanying proxy statement to “present in person” or “in person” shall mean virtually present at the Special Meeting, and all references in the accompanying proxy statement to “attend” shall mean virtually attend the Special Meeting.

On April 26, 2024, the Company entered into an Agreement and Plan of Merger (as it may be amended, modified or supplemented from time to time, the “Merger Agreement”), by and among Star Holding LLC, a Delaware limited liability company (“Parent”), Star Merger Co., a Delaware corporation and wholly owned subsidiary of Parent (“Merger Sub”) and U.S. Silica. The Merger Agreement provides, among other things, and subject to the terms and conditions set forth therein, that Merger Sub will be merged with and into U.S. Silica, with U.S. Silica surviving as a wholly owned subsidiary of Parent (the “Merger”). Parent and Merger Sub are affiliates of certain funds (the “Apollo Funds”) managed by affiliates of Apollo Global Management, Inc. (Apollo Global Management, Inc. and its subsidiaries collectively, “Apollo”). If the Merger is completed, U.S. Silica stockholders (other than stockholders who are entitled to demand and have properly demanded appraisal in accordance with, and who comply in all respects with, Section 262 of the General Corporation Law of the State of Delaware) will have the right to receive $15.50 in cash per share of U.S. Silica’s common stock, par value $0.01 per share (“Common Stock”), held immediately prior to the effective time of the Merger, without interest, less any applicable withholding taxes.

At the Special Meeting, you will be asked:

These items of business are more fully described in the accompanying proxy statement. The Company will transact no other business at the Special Meeting, except such business as may properly be brought before the Special Meeting by or at the direction of the Company’s board of directors (the “Board” or the “Board of Directors”).

Approval of the Merger Proposal requires the affirmative vote of the holders of a majority of the voting power represented by the outstanding shares (the “Shares”) of Common Stock that are entitled to vote on such proposal. Approval of each of the Merger Compensation Proposal and the Adjournment Proposal requires the affirmative vote of the majority of the voting power of the Shares present in person or represented by proxy at the Special Meeting and entitled to vote on such proposal.

The record date for the Special Meeting is      , 2024 (the “Record Date”). Only stockholders of record as of the close of business on the Record Date are entitled to notice of, and to vote at, the Special Meeting. Any stockholder entitled to attend and vote at the Special Meeting is entitled to appoint a proxy to attend and act on such stockholder’s behalf.

If the Merger is consummated, stockholders and beneficial owners who did not vote in favor of the Merger Proposal, submitted a written demand for appraisal prior to the vote on the Merger Proposal and otherwise complied with all other applicable requirements of Delaware law, will have the right to seek appraisal of the fair value of its Shares in accordance with Section 262 of the General Corporation Law of the State of Delaware (the “DGCL”). The procedures for exercising appraisal rights are summarized in the accompanying proxy statement and a copy of Section 262 of the DGCL may be accessed without subscription or cost at the following publicly available website: https://delcode.delaware.gov/title8/c001/sc09/index.html#262.

The obligations of U.S. Silica, Parent and Merger Sub to complete the Merger are subject to the satisfaction or waiver of several conditions set forth in the Merger Agreement. A copy of the Merger Agreement is attached as Annex A to the accompanying proxy statement, and you are encouraged to read it in its entirety.

The Board of Directors, after consulting with its financial advisor and outside legal counsel and reviewing and considering various factors described in “The Merger—Recommendation of Our Board of Directors and Reasons for the Merger,” on page 49 of the accompanying proxy statement, unanimously (i) determined that the transactions contemplated by the Merger Agreement, including the Merger, are advisable, fair to and in the best interests of U.S. Silica and its stockholders, (ii) approved, adopted and declared advisable the Merger Agreement and the transactions contemplated thereby, including the Merger, (iii) directed that the Merger Agreement be submitted to the stockholders of U.S. Silica for approval and adoption at the Special Meeting and (iv) recommended that U.S. Silica’s stockholders approve and adopt the Merger Agreement.

The Board of Directors unanimously recommends that you vote:

(1) “FOR” the Merger Proposal; (2) “FOR” the Merger Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

Your vote is very important! We cannot complete the Merger unless the Merger Proposal is approved by the affirmative vote of the holders of a majority of the voting power represented by the outstanding Shares that are entitled to vote on the Merger Proposal. Whether or not you plan to attend the Special Meeting, we urge you to read the accompanying proxy statement and vote as soon as possible via the Internet, by telephone or, if you receive a paper proxy card or voting instruction form in the mail, by mailing the completed proxy card or voting instruction form.

If you hold your Shares in “street name,” you should instruct your bank, broker or other nominee how to vote your Shares in accordance with the voting instructions that you will receive from your bank, broker or other nominee. Your bank, broker or other nominee cannot vote on any of the proposals, including the Merger Proposal, without your instructions.

If you fail to submit your proxy or voting instructions, or to attend the Special Meeting and vote during the Special Meeting, your Shares will not be counted for purposes of determining whether a quorum is present at the Special Meeting and, if a quorum is present, will have the same effect as a vote “AGAINST” the Merger Proposal, but will have no effect on the Merger Compensation Proposal or the Adjournment Proposal.

The accompanying proxy statement provides detailed information about the Special Meeting, the Merger Agreement and the Merger. A copy of the Merger Agreement is attached as Annex A to the accompanying proxy statement. We encourage you to carefully read the entire proxy statement and its annexes, including the Merger Agreement and the documents referred to or incorporated by reference in the accompanying proxy statement. You may also obtain additional information about the Company from other documents we have filed with the U.S. Securities and Exchange Commission (the “SEC”). In particular, you should read the “Risk Factors” section beginning on page 26 of the accompanying proxy statement and beginning on page 11 of our Annual Report on Form 10-K for the year ended December 31, 2023, and other risk factors detailed from time to time in the Company’s reports filed with the SEC and incorporated by reference in the accompanying proxy statement, for risks relating to our business and for a discussion of the risks that you should consider in evaluating the proposed transaction and how it may affect you.

If you have any questions or need assistance voting your Shares, please contact our proxy solicitor:

INNISFREE M&A INCORPORATED

501 Madison Avenue, 20^th Floor

New York, New York 10022

Stockholders may call toll-free: (877) 750-8269

Banks and brokers may call collect: (212) 750-5833

Thank you for your continued support of U.S. Silica.

Sincerely,

NEITHER THE SEC NOR ANY STATE SECURITIES REGULATORY AGENCY HAS APPROVED OR DISAPPROVED THE MERGER, PASSED UPON THE MERITS OR FAIRNESS OF THE MERGER AGREEMENT OR THE TRANSACTIONS CONTEMPLATED BY THE MERGER AGREEMENT, OR PASSED UPON THE ADEQUACY OR ACCURACY OF THE INFORMATION CONTAINED IN THIS DOCUMENT. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

The accompanying proxy statement is dated     , 2024, and is first being mailed to the Company’s stockholders on or about     , 2024.

U.S. Silica Holdings, Inc.

24275 Katy Freeway, Suite 600

Katy, TX 77494

NOTICE OF SPECIAL MEETING OF STOCKHOLDERS

TO BE HELD  , 2024

Dear U.S. Silica Stockholder:

You are cordially invited to attend a special meeting (we refer to such meeting, including any adjournment or postponement thereof, as the “Special Meeting”) of the stockholders of U.S. Silica Holdings, Inc. (“U.S. Silica” or the “Company”) to be held virtually via live webcast on     , 2024, at     , Central Time. You will be able to virtually attend and vote at the Special Meeting by visiting     . Please note that you will not be able to attend the Special Meeting physically in person. For purposes of attendance at the Special Meeting, all references in the accompanying proxy statement to “present in person” or “in person” shall mean virtually present at the Special Meeting, and all references in the accompanying proxy statement to “attend” shall mean virtually attend the Special Meeting.

The Special Meeting will be held for the following purposes:

These items of business are more fully described in the proxy statement of which this notice forms a part. The Company will transact no other business at the Special Meeting, except such business as may properly be brought before the Special Meeting by or at the direction of the Company’s board of directors (the “Board” or the “Board of Directors”).

Approval of the Merger Proposal requires the affirmative vote of the holders of a majority of the voting power represented by the outstanding shares (the “Shares”) of U.S. Silica’s common stock, par value $0.01 per share (“Common Stock”), that are entitled to vote on such proposal. Approval of each of the Merger Compensation Proposal and the Adjournment Proposal requires the affirmative vote of the majority of the voting power of the Shares present in person or represented by proxy at the Special Meeting and entitled to vote on such proposal.

The record date for the Special Meeting is     , 2024 (the “Record Date”). Only stockholders of record as of the close of business on the Record Date are entitled to notice of, and to vote at, the Special Meeting.

Any stockholder entitled to attend and vote at the Special Meeting is entitled to appoint a proxy to attend and act on such stockholder’s behalf.

If the Merger is consummated, stockholders and beneficial owners who did not vote in favor of the Merger Proposal, submitted a written demand for appraisal prior to the vote on the Merger Proposal and otherwise complied with all other applicable requirements of Delaware law, will have the right to seek appraisal of the fair value of their Shares in accordance with Section 262 of the General Corporation Law of the State of Delaware (the “DGCL”). The procedures for exercising appraisal rights are summarized in the accompanying proxy statement and a copy of Section 262 of the DGCL may be accessed without subscription or cost at the following publicly available website: https://delcode.delaware.gov/title8/c001/sc09/index.html#262.

The obligations of U.S. Silica, Parent and Merger Sub to complete the Merger are subject to the satisfaction or waiver of several conditions set forth in the Merger Agreement. A summary of the Merger Agreement is included in the accompanying proxy statement under the caption “The Merger Agreement (The Merger Proposal)” and a copy of the Merger Agreement is attached as Annex A to the accompanying proxy statement, each of which is incorporated by reference into this notice. You are encouraged to read the Merger Agreement in its entirety.

The Board of Directors, after consulting with its financial advisor and outside legal counsel and reviewing and considering various factors described in “The Merger—Recommendation of Our Board of Directors and Reasons for the Merger,” on page 49 of the accompanying proxy statement, unanimously (i) determined that the transactions contemplated by the Merger Agreement, including the Merger, are advisable, fair to and in the best interests of U.S. Silica and its stockholders, (ii) approved, adopted and declared advisable the Merger Agreement and the transactions contemplated thereby, including the Merger, (iii) directed that the Merger Agreement be submitted to the stockholders of U.S. Silica for approval and adoption at the Special Meeting and (iv) recommended that U.S. Silica’s stockholders approve and adopt the Merger Agreement.

The Board of Directors unanimously recommends that you vote:

Your vote is very important! We cannot complete the Merger unless the Merger Proposal is approved by the affirmative vote of the holders of a majority of the voting power represented by the outstanding Shares that are entitled to vote on the Merger Proposal. Whether or not you plan to attend the Special Meeting, we urge you to read the enclosed proxy statement and vote as soon as possible via the Internet, by telephone or, if you receive a paper proxy card or voting instruction form in the mail, by mailing the completed proxy card or voting instruction form.

If you hold your Shares in “street name,” you should instruct your bank, broker or other nominee how to vote your Shares in accordance with the voting instructions that you will receive from your bank, broker or other nominee. Your bank, broker or other nominee cannot vote on any of the proposals, including the Merger Proposal, without your instructions.

If you fail to submit your proxy or voting instructions, or to attend the Special Meeting and vote during the Special Meeting, your Shares will not be counted for purposes of determining whether a quorum is present at the Special Meeting and, if a quorum is present, will have the same effect as a vote “AGAINST” the Merger Proposal, but will have no effect on the Merger Compensation Proposal or the Adjournment Proposal.

The accompanying proxy statement provides detailed information about the Special Meeting, the Merger Agreement and the Merger. A copy of the Merger Agreement is attached as Annex A to the proxy statement. The accompanying proxy statement, including the copy of the Merger Agreement attached thereto as Annex A, is incorporated by reference into this Notice of Special Meeting of Stockholders. We encourage you to carefully read the entire proxy statement and its annexes, including the Merger Agreement and the documents referred to or incorporated by reference in the accompanying proxy statement. You may also obtain additional information

about the Company from other documents we have filed with the U.S. Securities and Exchange Commission (the “SEC”). In particular, you should read the “Risk Factors” section beginning on page 26 of the accompanying proxy statement and beginning on page 11 of our Annual Report on Form 10-K for the year ended December 31, 2023, and other risk factors detailed from time to time in the Company’s reports filed with the SEC and incorporated by reference in the accompanying proxy statement, for risks relating to our business and for a discussion of the risks that you should consider in evaluating the proposed transaction and how it may affect you.

If you have any questions or need assistance voting your Shares, please contact our proxy solicitor:

INNISFREE M&A INCORPORATED

501 Madison Avenue, 20th Floor

New York, New York 10022

Stockholders may call toll-free: (877) 750-8269

Banks and brokers may call collect: (212) 750-5833

Stacy Russell

Executive Vice President, General Counsel & Corporate

Secretary

   , 2024

Important Notice Regarding the Availability of Proxy Materials for the Special Meeting to Be Held on   , 2024.

The Notice of Special Meeting of Stockholders and accompanying Proxy Statement are available at www.proxyvote.com.

TABLE OF CONTENTS

i

1

2

3

4

5

6

7

8

9

10

11

12

13

14

QUESTIONS AND ANSWERS ABOUT THE SPECIAL MEETING AND THE MERGER

The following questions and answers briefly address some commonly asked questions about the Special Meeting, the Merger Agreement and the Merger and the proposals being considered at the Special Meeting. These questions and answers do not contain all of the details that may be important to you as a U.S. Silica Stockholder. Therefore, U.S. Silica encourages you to carefully read this entire proxy statement, its annexes and the documents referred to or incorporated by reference in this proxy statement. You may obtain the information incorporated by reference without charge by following the instructions under “Where You Can Find More Information” on page 126 of this proxy statement.

Why is U.S. Silica sending this proxy statement and proxy card?

On April 26, 2024, U.S. Silica entered into the Merger Agreement providing for the merger of Merger Sub with and into U.S. Silica, with U.S. Silica surviving as a privately held, wholly owned subsidiary of Parent (the “Merger”). The Board of Directors is soliciting the vote of the U.S. Silica Stockholders to approve the Merger Proposal and the other matters to be voted on at the Special Meeting. The Merger cannot occur without the required approval of U.S. Silica Stockholders. In addition to the approval and adoption of the Merger Agreement, the Board is soliciting the vote of the U.S. Silica Stockholders to approve each of the other proposals described below in “—What matters will be voted on at the Special Meeting?”

When and Where is the Special Meeting?

The Special Meeting will be held online at     on     , 2024, at     , Central Time. There will not be a physical meeting location. We encourage you to access the Special Meeting prior to the start time. Online check-in will begin at Central Time, and you should allow reasonable time for the check-in procedures. To attend the Special Meeting, you will need to log in to using the 16-digit control number on the proxy card or voting instruction form. If you encounter any difficulties accessing the Special Meeting during the check-in process or encounter any other technical difficulties with the Special Meeting during the check-in process, please call the technical support number that will be posted on the Special Meeting login page. For more information about the Special Meeting, see “The Special Meeting,” beginning on page 29 of this proxy statement.

What matters will be voted on at the Special Meeting?

At the Special Meeting, U.S. Silica Stockholders will consider and vote on the following matters:

If the U.S. Silica Stockholders approve the Merger Proposal and the Merger is completed, U.S. Silica will become a wholly owned subsidiary of Parent at the Effective Time.

If the Merger is completed, what will I be entitled to receive for my Shares?

If the Merger is completed, U.S. Silica Stockholders immediately prior to the Effective Time will be entitled to receive the Merger Consideration of $15.50 in cash for each Share they own, unless you are entitled to demand

15

and have properly demanded appraisal for your Shares in accordance with, and you comply in all respects with, Section 262 of the DGCL, in which case you will be entitled to the rights provided by Section 262 of the DGCL, which may be accessed without subscription or cost at the following publicly available website: https://delcode.delaware.gov/title8/c001/sc09/index.html#262. The Merger Consideration will be payable in cash (without interest) and subject to any applicable withholding taxes required by applicable law.

How does the Merger Consideration compare to the market price of the Common Stock prior to the public announcement of the Merger Agreement?

The Merger Consideration represents a premium of 18.7% to the closing price of the Common Stock on April 25, 2024, the last trading day before the Merger Agreement was announced, and a premium of 33% over the 90-day volume-weighted average for the period ended April 25, 2024.

If the Merger is completed, what will I be entitled to receive for my Company PSUs, my Company RSUs or my Company Options?

At the Effective Time and as a result of the Merger:

Am I entitled to appraisal rights?

As a holder or beneficial owner of Shares, you are entitled to exercise appraisal rights under the DGCL in connection with the Merger if you take certain actions and meet certain conditions set forth in Section 262 of the DGCL. If the Merger is consummated, U.S. Silica Stockholders and beneficial owners of Shares who do not vote in favor of the approval and adoption of the Merger Agreement and who properly exercise and perfect his, her, its, or their demand for appraisal rights under Section 262 of the DGCL shall be entitled to receive such consideration as shall be determined pursuant to Section 262 of the DGCL. This means that U.S. Silica

16

Stockholders and beneficial owners are entitled to have their Shares appraised by the Delaware Court of Chancery and to receive payment in cash of the “fair value” of the Shares, exclusive of any elements of value arising from the accomplishment or expectation of the Merger, together with interest to be paid based upon the amount determined to be fair value, if any, as determined by the Delaware Court of Chancery. U.S. Silica Stockholders and beneficial owners who wish to seek appraisal of their Shares are in any case encouraged to seek the advice of legal counsel with respect to the exercise of appraisal rights due to the complexity of the appraisal process. Failure to timely and properly comply with Section 262 of the DGCL may result in the loss or waiver of your appraisal rights. See the section entitled “The Merger—Appraisal Rights” beginning on page 32 of this proxy statement, which is qualified in its entirety by Section 262 of the DGCL, the relevant section of the DGCL regarding appraisal rights. A copy of Section 262 of the DGCL is accessible, without subscription or cost, at the following publicly available website: https://delcode.delaware.gov/title8/c001/sc09/index.html#262 and is incorporated by reference herein to this proxy statement.

Is the Merger subject to the satisfaction of any conditions?

Yes. In addition to the approval of the Merger Proposal by the U.S. Silica Stockholders, the Merger is subject to the satisfaction of various conditions. For a description of these conditions, please see the section entitled “The Merger Agreement (The Merger Proposal)—Conditions to Closing of the Transaction” beginning on page 112 of this proxy statement.

When is the Merger expected to be completed?

In order to complete the Merger, U.S. Silica must obtain the approval of the Merger Proposal as described in this proxy statement and the other closing conditions under the Merger Agreement must be satisfied, including the receipt of applicable regulatory approvals. U.S. Silica currently expects to complete the Merger in the third quarter of 2024. However, U.S. Silica cannot assure you that the Merger will be completed by any particular date.

What happens if the Merger is not completed?

If the Merger Proposal is not approved by the requisite vote of U.S. Silica Stockholders, or if the Merger is not consummated for any other reason, the U.S. Silica Stockholders will not receive any Merger Consideration. Instead, U.S. Silica will remain a public company, its Common Stock will continue to be listed and traded on the NYSE and registered under the Exchange Act, and it will continue to file periodic reports with the SEC.

Under specified circumstances, U.S. Silica may be required to pay Parent a termination fee, or may be entitled to receive a reverse termination fee from Parent, upon the termination of the Merger Agreement, as described in “The Merger Agreement (The Merger Proposal)— Company Termination Fee, Parent Expense Reimbursement, Reverse Termination Fee” on page 115 of this proxy statement.

Will I be subject to U.S. federal income taxation upon the exchange of my Shares for the Merger Consideration?

Other than with respect to U.S. Silica equity-based compensatory arrangements, which are described in the next question and answer below, the material U.S. federal income tax consequences of the Merger are described in “The Merger—Material U.S. Federal Income Tax Consequences of the Merger” beginning on page 81 of this proxy statement. If you are a U.S. holder (as defined in “The Merger— Material U.S. Federal Income Tax Consequences of the Merger—Tax Consequences to U.S. Holders”), the exchange of your Shares for cash pursuant to the Merger will generally require you to recognize gain or loss for U.S. federal income tax purposes in an amount equal to the difference, if any, between the amount of cash you receive for such Shares (determined before the deduction of any applicable withholding taxes) and your adjusted tax basis in such Shares.

17

If you are a non-U.S. holder (as defined in “The Merger—Material U.S. Federal Income Tax Consequences of the Merger—Tax Consequences to Non-U.S. Holders”), the exchange of your Shares for cash pursuant to the Merger will generally not be subject to U.S. federal income taxation unless (1) you have certain connections to the United States or (2) U.S. Silica is, or was during the relevant period, a U.S. real property holding corporation.

A more complete description of the material U.S. federal income tax consequences of the Merger is provided in “The Merger—Material U.S. Federal Income Tax Consequences of the Merger” beginning on page 81 of this proxy statement. You should consult your tax advisor concerning the U.S. federal income tax consequences to you of the Merger in light of your particular circumstances, as well as any consequences arising under the U.S. federal tax laws other than those pertaining to income tax, including estate or gift tax laws, or under any state, local or non-U.S. tax law or under any applicable income tax treaty.

What tax consequences will there be relating to my Company RSUs, Company PSUs and Company Options?

If you hold Company RSUs, Company PSUs or Company Options immediately prior to the Effective Time, then you will generally recognize taxable income for U.S. federal income tax purposes equal to the cash payment you receive for your Company RSUs, Company PSUs and Company Options. This will be treated as ordinary compensation income for U.S. federal income tax purposes and subject to income and other payroll tax withholding. Company RSUs, Company PSUs and Company Options that are forfeited prior to closing (pursuant to termination of employment or otherwise) will not be entitled to any consideration at the close of the Merger.

If you previously received Common Stock in settlement of Company RSUs, Company PSUs or Company Options and already recognized ordinary income on such Common Stock at the time of such settlement, then you will generally recognize a capital gain or loss for U.S. federal income tax purposes equal to the difference between the income you previously recognized and the amount paid for the stock in the Merger. The capital gain or loss will be long-term if more than one year has expired between the time you recognized the income and the Merger. Holders of such Common Stock received in settlement of Company RSUs, Company PSUs or Company Options generally will not be subject to income or other payroll tax withholding on any such capital gain.

What effect will the Merger have on U.S. Silica and its Common Stock?

The Common Stock is currently registered under the Exchange Act and is traded on the NYSE under the symbol “SLCA.” As a result of the Merger, U.S. Silica will become a privately held, wholly owned subsidiary of Parent. As such, following the completion of the Merger, the registration of the Common Stock and U.S. Silica’s obligation to file reports and make other public disclosures to the SEC under the Exchange Act will be terminated, and the Common Stock will no longer be listed on the NYSE. U.S. Silica Stockholders will cease to have any equity interest in U.S. Silica and will have no right to participate in its earnings and future growth.

Why am I being asked to cast a non-binding advisory vote to approve the compensation that may be paid or become payable to the named executive officers of U.S. Silica in connection with the Merger?

Section 14A of the Exchange Act requires U.S. Silica to conduct a non-binding advisory vote with respect to certain “golden parachute” compensation that may be paid or become payable to U.S. Silica’s named executive officers in connection with the Merger, including the agreements and understandings with U.S. Silica pursuant to which such compensation may be paid or become payable.

What will happen if the stockholders do not approve the Merger Compensation Proposal at the Special Meeting?

Approval of the Merger Compensation Proposal is not a condition to the completion of the Merger. The vote with respect to the Merger Compensation Proposal is on an advisory basis and will not be binding on U.S. Silica or Parent. Further, the underlying compensation plans and agreements are contractual in nature and are not, by their terms, subject to stockholder approval.

18

How does the Board of Directors recommend that I vote on the proposals?

After consulting with its financial advisors and outside legal counsel and after reviewing and considering the terms and conditions of the Merger and the factors more fully described in the enclosed proxy statement, the Board unanimously (i) determined that the transactions contemplated by the Merger Agreement, including the Merger, are advisable, fair to, and in the best interests of, U.S. Silica and its stockholders, (ii) approved, adopted and declared advisable the Merger Agreement and the transactions contemplated thereby, including the Merger, (iii) directed that the Merger Agreement be submitted to the U.S. Silica Stockholders for approval and adoption, and (iv) recommended that the U.S. Silica Stockholders approve and adopt the Merger Agreement.

Accordingly, the Board of Directors unanimously recommends that you vote:

To review the Board’s reasons for recommending the Merger, see the section entitled “The Merger—Recommendation of Our Board of Directors and Reasons for the Merger” beginning on page 49 of this proxy statement.

Do any of U.S. Silica’s directors and executive officers have interests in the Merger that may differ from or be in addition to my interests as a stockholder?

Yes. In considering the recommendation of the Board of Directors with respect to the Merger Proposal, you should be aware that U.S. Silica’s directors and executive officers may have interests in the Merger that are different from, or in addition to, the interests of U.S. Silica Stockholders generally. To the extent such interests existed at the time, the Board of Directors was aware of and considered these interests, among other matters, in evaluating and negotiating the Merger Agreement and the Merger, and in recommending that the Merger Agreement be approved and adopted by the U.S. Silica Stockholders. See the section entitled “The Merger—Interests of the Directors and Officers of U.S. Silica in the Merger” beginning on page 66 of this proxy statement.

What is the difference between holding Shares as a stockholder of record and as a beneficial owner?

If your Shares are registered directly in your name with our transfer agent, Broadridge Corporate Issuer Solutions, Inc., you are considered, with respect to those Shares, the “stockholder of record.” In this case, this proxy statement and your proxy card have been sent directly to you by U.S. Silica.

If your Shares are held in a stock brokerage account or by a bank or other record holder, you are considered the “beneficial owner” of Shares held in “street name.” In that case, this proxy statement has been forwarded to you by your bank, broker or other nominee. As the beneficial owner, you have the right to direct your broker, bank or other record holder on how to vote your Shares, and you are also invited to attend the Special Meeting. Your broker, bank or other record holder should have enclosed or provided voting instructions for you to use in directing the voting of your Shares.

Who is entitled to vote at the Special Meeting?

Only holders of record of our Common Stock at the close of business on     , 2024, the Record Date, are entitled to notice of the Special Meeting and to vote at the Special Meeting or at any adjournment or postponement thereof. There were      Shares outstanding on     , 2024. Stockholders are entitled to cast one vote per Share owned at the close of business on the Record Date on all matters. Virtual attendance at the Special Meeting is not required to vote.

19

How do I vote my Shares during the Special Meeting?

Even if you currently plan to attend the Special Meeting, we recommend that you submit your proxy or voting instructions in advance as described below to ensure that your vote will be counted if you later decide not to attend the Special Meeting.

During the Special Meeting, you may vote Shares held in your name as the stockholder of record or held in street name as the beneficial owner by following the instructions available on the meeting website.

How do I vote my Shares without attending the Special Meeting?

There are three ways to vote by proxy:

The availability of telephone and internet voting will depend on the bank’s, broker’s or other nominee’s voting process. Your bank, broker or other nominee will not be permitted to exercise voting discretion as to any of the matters to be acted upon, including on the Merger Proposal. Therefore, it is important that you provide your voting instructions to your bank, broker or other nominee to ensure your Shares are represented at the Special Meeting.

Stockholders may generally vote via the internet or by telephone until 11:59 p.m. Eastern Time, on     , 2024, or the Company’s tabulation agent must receive paper proxy cards on or before     , 2024. However, voting deadlines may vary depending on how you hold your Shares, so please carefully review the specific instructions provided on your proxy card or voting instruction form.

How will my proxy be voted?

All properly completed, unrevoked proxies that are timely received will be voted in accordance with the specifications made.

If a properly executed, unrevoked written proxy card does not specifically direct the voting of Shares covered, the proxy will be voted:

If any other business properly comes before the meeting, or any adjournment thereof, the persons named as proxies will vote your Shares in accordance with the recommendations of the Board of Directors.

May I revoke or change my vote?

If you are a stockholder of record, you may revoke your proxy at any time before it is actually voted by giving written notice of revocation to our Corporate Secretary, by delivering a proxy bearing a later date (including by telephone or by internet), provided such proxy card is received no later than the close of business on     , 2024, by voting again by telephone or the Internet before the closing of the voting facilities at p.m. Central Time on     , 2024 or by attending and voting during the Special Meeting. Attendance at the Special Meeting will not cause your previously granted proxy to be revoked unless you specifically make that request. If you are a beneficial owner of Shares, you may submit new voting instructions by contacting your bank, broker or other record holder.

20

Will my vote be made public?

All proxies and voting materials that identify the votes of specific stockholders will generally be kept confidential, except as necessary to meet applicable legal requirements and to allow for the tabulation of votes and certification of the vote.

What constitutes a quorum, permitting the Special Meeting to conduct its business?

The presence at the Special Meeting, in person or by proxy, of the holders record of a majority of the outstanding voting power of the Shares entitled to vote, present in person or represented by proxy, as of the Record Date is considered a quorum for the transaction of business. If you submit a properly completed proxy or if you attend the Special Meeting to vote during the meeting, your Shares will be considered part of the quorum.

What is the effect of abstentions and broker non-votes?

Abstentions are counted as present and entitled to vote for purposes of determining a quorum. If a quorum is present at the Special Meeting, for a U.S. Silica Stockholder who attends the Special Meeting or is represented by proxy and abstains from voting, such abstention will have the same effect as if the U.S. Silica Stockholder voted “AGAINST” the Merger Proposal, the Merger Compensation Proposal and the Adjournment Proposal.

“Broker non-votes” will also count as a vote “AGAINST” the Merger Proposal but will have no effect on the Merger Compensation Proposal or the Adjournment Proposal, because broker non-votes will not be counted as Shares present and entitled to vote with respect to proposals on which the broker has not voted. A broker non-vote occurs when a bank, broker or other nominee holding Shares for a beneficial owner does not vote on a particular proposal because that holder does not have discretionary voting power for that particular item and has not received instructions from the beneficial owner.

The Merger Proposal, Merger Compensation Proposal and Adjournment Proposal are “non-discretionary” items. If you do not instruct your bank, broker or other nominee how to vote with respect to any of these items, your bank, broker or other nominee may not vote with respect to the applicable proposal and those votes will be counted as “broker non-votes.”

How many votes are needed to approve a proposal?

Assuming the presence of a quorum, the affirmative vote of the holders of a majority of the voting power represented by the outstanding Shares that are entitled to vote thereon is required for the approval of the Merger Proposal.

Assuming the presence of a quorum, the affirmative vote of a majority of the voting power represented by the Shares present, in person or by proxy, at the Special Meeting and entitled to vote is required to: (i) approve the Merger Compensation Proposal, and (ii) approve the Adjournment Proposal. Because the vote standard for the approval of these proposals is a majority of Shares present at the Special Meeting in person or represented by proxy and entitled to vote, abstentions have the effect of a vote “AGAINST” the proposals and broker non-votes have no effect on the proposals.

Should I send in my U.S. Silica stock certificates or other evidence of ownership now?

No. After the Merger is completed, the paying agent to be engaged by Parent in connection with the Merger will send to each U.S. Silica Stockholder written, detailed instructions for exchanging your stock certificates for the Merger Consideration. You must return your stock certificates as described in the instructions. If your Shares are held in “street name” by your broker, bank or other nominee, you may receive instructions from the broker, bank or other nominee as to what action, if any, you need to take to effect the exchange of your “street name” Shares for the Merger Consideration. Please do not send in any certificates now.

21

What happens to my vote if I sell my Shares before the Special Meeting?

The Record Date is earlier than both the date of the Special Meeting and the consummation of the Merger. If you transfer your Shares after the Record Date but before the Special Meeting, unless special arrangements (such as provision of a proxy) are made between you and the person to whom you transfer your Shares and each of you notifies U.S. Silica in writing of such special arrangements, you will retain your right to vote such Shares at the Special Meeting but will transfer the right to receive the Merger Consideration to the person to whom you transfer your Shares. Even if you sell or otherwise transfer your Shares after the Record Date, we encourage you to vote in accordance with the instructions detailed in the section of this proxy statement entitled “—Voting at the Special Meeting.”

How can I obtain a proxy card?

If you lose, misplace or otherwise need to obtain a proxy card, please follow the applicable procedure below. For stockholders of record: Please call Innisfree M&A Incorporated at (877) 750-8269 (toll-free).

For holders in “street name”: Please contact your broker, bank, or other nominee.

What should I do if I receive more than one set of voting materials?

This means you own Shares that are registered under different names or are in more than one account. For example, you may own some Shares directly as a stockholder of record and other Shares through a broker, or you may own Shares through more than one broker. In these situations, you will receive multiple sets of proxy materials. You must vote, sign and return all of the proxy cards or follow the instructions for any alternative voting procedure on each of the proxy cards that you receive in order to vote all of the Shares you own. Each proxy card you receive comes with its own return envelope. If you submit your proxy by mail, make sure you return each proxy card in the return envelope that accompanies that proxy card.

Who will count the vote?

Representatives of Broadridge Corporate Issuer Solutions, Inc. will tabulate the votes and act as inspectors of election.

How can I find the voting results of the Special Meeting?

We will report the voting results in a Current Report on Form 8-K within four business days after the end of the Special Meeting.

How is the solicitation being made?

The cost of solicitation of proxies will be borne by us. Solicitation will be made by mail, and may be made by directors, officers and employees, personally or by telephone, email or fax. Proxy cards and materials also will be distributed to beneficial owners of stock through brokers, custodians, nominees and other like parties, and we expect to reimburse such parties for their charges and expenses. We have engaged Innisfree M&A Incorporated to assist us in the solicitation of proxies, at an estimated cost of $40,000 plus expense reimbursement.

Where can I find more information about U.S. Silica?

We file reports and other information with the SEC. This information is available at our website at http://www.ussilica.com and at the internet site maintained by the SEC at http://www.sec.gov. The information contained in, or that can be accessed through, our website (http://www.ussilica.com) is not part of this proxy statement and is not incorporated in this proxy statement by this or any other reference to our website provided in this proxy statement.

22

Who can help answer my questions?

If you have any questions concerning the Merger, the Special Meeting or this proxy statement, would like additional copies of this proxy statement or need help voting your Shares, please contact our proxy solicitor:

INNISFREE M&A INCORPORATED

501 Madison Avenue, 20th Floor

New York, New York 10022

Stockholders may call toll-free: (877) 750-8269

Banks and brokers may call collect: (212) 750-5833

23

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement, and the documents to which we refer you in this proxy statement, as well as information included in oral statements or other written statements made or to be made by us or on our behalf, may include “forward-looking” statements within the meaning of the U.S. securities laws, including Section 27A of the Securities Act and Section 21E of the Exchange Act, that do not directly or exclusively relate to historical facts, including, without limitation, statements relating to the completion of the Merger. Forward-looking statements generally include statements that are predictive in nature and depend upon or refer to future events or conditions, and include words such as “believes,” “plans,” “anticipates,” “projects,” “estimates,” “seeks,” “targets,” “expects,” “intends,” “strategy,” “future,” “likely,” “continue,” “opportunity,” “may,” “might,” “will,” “would,” “should,” “could,” “potential” or other similar expressions, or the negative of these terms or comparable terminology. These statements are based on current beliefs and assumptions that are subject to risks and uncertainties. Actual results could differ materially from those contained in any forward-looking statement as a result of various factors, including, without limitation:

24

The foregoing review of important factors that could cause actual results to differ from expectations should not be construed as exhaustive and should be read in conjunction with the information contained or incorporated by reference herein, including, but not limited to, (i) the information contained under this heading and (ii) the information contained under the heading “Risk Factors” and information in our consolidated financial statements and notes thereto included in our filings with the SEC, including our Annual Report on Form 10-K for the year ended December 31, 2023. See “Where You Can Find More Information” on page 126 of this proxy statement. No assurance can be given that these are all of the factors that could cause actual results to vary materially from the forward-looking statements.

The statements in this proxy statement are made as of the date set forth above, even if subsequently made available by the Company on its website or otherwise. Except as required by applicable law, we do not intend, and assume no obligation, to update any forward-looking statements. U.S. Silica Stockholders are advised, however, to consult any future disclosures we make on related subjects as may be detailed in our other filings made from time to time with the SEC.

All information contained in this proxy statement exclusively concerning Parent, Merger Sub and their affiliates has been supplied by Parent and Merger Sub and has not been independently verified by us.

25

RISK FACTORS

In addition to the other information included and incorporated by reference into this proxy statement, including the matters addressed in the section entitled “Cautionary Statement Regarding Forward-Looking Statements” beginning on page 24 of this proxy statement, you should be aware of and carefully consider the following risks and uncertainties that are applicable to the Merger Agreement, the Merger and U.S. Silica before deciding whether to vote for the Merger Proposal, the Merger Compensation Proposal and the Adjournment Proposal. You should also consider the risks relating to the business of U.S. Silica and ownership of Common Stock contained in Part I, Item 1A of U.S. Silica’s Annual Report on Form 10-K for the year ended December 31, 2023, as well as any subsequent documents filed by U.S. Silica with the SEC, which are incorporated into this proxy statement by reference. See the section entitled “Where You Can Find More Information” beginning on page 126 of this proxy statement.

The Merger is subject to receipt of approval from our stockholders as well as the satisfaction of other closing conditions, including conditions that may not be satisfied or completed within the expected timeframe, if at all.

The consummation of the Merger is subject to a number of important closing conditions that make the closing and timing of the Merger uncertain. These conditions include, among others, (i) the approval and adoption of the Merger Agreement by holders of a majority of the voting power represented by the Shares that are outstanding and entitled to vote thereon at the Special Meeting; (ii) the absence of any law, order, injunction or decree that restrains, enjoins or otherwise prohibits or makes illegal the consummation of the transactions contemplated by the Merger Agreement; and (iii) the expiration or termination of any applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended. We can provide no assurance that all required consents and approvals will be obtained or that all closing conditions will otherwise be satisfied (or waived, if applicable), and, if all required consents and approvals are obtained and all closing conditions are satisfied (or waived, if applicable), we can provide no assurance as to the terms, conditions and timing of such consents and approvals or the timing of the completion of the Merger. Many of the conditions to completion of the Merger are not within either our or Parent’s control, and neither we nor Parent can predict when or if these conditions will be satisfied (or waived, if applicable).

Failure to complete the Merger in a timely manner, or at all, could negatively impact our future business and our financial condition, results of operations and cash flows.

The Merger may not be completed within the expected timeframe, or at all, as a result of various factors and conditions, some of which may be beyond our control. If the Merger is not completed for any reason, including as a result of our stockholders failing to approve and adopt the Merger Agreement, our stockholders will not receive any payment for their Shares in connection with the Merger. Instead, the Company will remain an independent public company, and its Shares will continue to be traded on the NYSE and registered under the Exchange Act, and we will be required to continue to file periodic reports with the SEC. Moreover, our ongoing business may be materially adversely affected and we would be subject to a number of risks, including the following:

26

If the Merger is not consummated, the risks described above may materialize and they may have a material adverse effect on our business operations, financial results and stock price, especially to the extent that the current market price of our Common Stock reflects an assumption that the Merger will be completed.

We are subject to certain restrictions in the Merger Agreement that may hinder operations pending the consummation of the Merger.

The Merger Agreement generally requires us to operate our business in the ordinary course pending consummation of the Merger and restricts us, without Parent’s consent, from taking certain specified actions until the Merger is completed, subject to certain exceptions. These restrictions may affect our ability to execute our business strategies and attain our financial and other goals and may impact our financial condition, results of operations and cash flows.

These restrictions could be in place for an extended period of time if the consummation of the Merger is delayed, which may delay or prevent us from undertaking business opportunities that, absent the Merger Agreement, we might have pursued, or from effectively responding to competitive pressures or industry developments.

Whether or not the Merger is completed, the pending Merger may disrupt our current plans and operations, which could have an adverse effect on our business and financial results. For these and other reasons, the pendency of the Merger could adversely affect our business and financial results. For more information, see “The Merger Agreement (The Merger Proposal) — Conduct of Business Prior to Closing” on page 94 of this proxy statement.

We will be subject to various uncertainties while the Merger is pending that may cause disruption and may make it more difficult to maintain relationships with employees, clients, customers, and others with whom we do business.

Our efforts to complete the Merger could cause substantial disruptions in, and create uncertainty surrounding, our business, which may materially adversely affect our results of operation and our business. In connection with the Merger, our current and prospective employees may experience uncertainty about their future roles with the Surviving Corporation following the Merger, which may materially adversely affect our ability to attract and retain key personnel while the Merger is pending. Key employees may depart because of issues relating to the uncertainty and difficulty transitioning to a private company with a new owner. Accordingly, no assurance can be given that we will be able to attract and retain key employees to the same extent that we have been able to in the past. If we do not succeed in attracting, hiring, and integrating excellent personnel, or retaining and motivating existing personnel, we may be unable to grow and operate our business effectively.

27

As mentioned above, some amount of our management’s and employees’ attention is being directed toward the completion of the Merger and thus is being diverted from our day-to-day operations. The Merger further could cause disruptions to our business or business relationships, which could have an adverse impact on our results of operations. Parties with which we have business relationships may experience uncertainty as to the future of such relationships and may delay or defer certain business decisions, seek alternative relationships with third parties or seek to alter their present business relationships with us. Parties with whom we otherwise may have sought to establish business relationships may seek alternative relationships with third parties. The pursuit of the Merger and the preparation for the integration may also place a significant burden on management and internal resources. The diversion of management’s attention away from day-to-day business concerns could adversely affect our financial results.

The Merger Agreement contains provisions that could discourage a potential competing acquirer of us.

The Merger Agreement contains non-solicitation provisions that, upon expiration of the go-shop period and subject to limited exceptions, restrict our ability to solicit, initiate, or knowingly encourage or induce competing third-party proposals (or engage in, continue or otherwise participate in negotiations or discussions regarding such third-party proposals) for the acquisition of our stock or assets. Under certain limited circumstances, the Board may (i) withdraw, qualify or modify its recommendation that U.S. Silica Stockholders approve and adopt the Merger Agreement or (ii) terminate the Merger Agreement to enter into a definitive agreement with respect to a third-party acquisition proposal. However, before doing so, the Board must abide by certain procedures described in the Merger Agreement, including provisions that give Parent an opportunity to negotiate to modify the terms of the Merger Agreement in a manner that any such third-party acquisition proposal would not constitute a superior proposal. In some circumstances, upon termination of the Merger Agreement, we will be required to pay a termination fee to Parent of up to $41.75 million. For more information, please see the section of this proxy statement entitled “The Merger Agreement (The Merger Proposal)—Company Termination Fee, Parent Expense Reimbursement, Reverse Termination Fee.”

These provisions could discourage a potential third-party acquirer that might have an interest in acquiring all or a significant portion of us from considering or proposing that acquisition, even if the acquirer was prepared to pay consideration with a higher per share cash or market value than the market value proposed to be received or realized in the Merger, or might otherwise result in a potential third-party acquirer proposing to pay a lower price to U.S. Silica Stockholders than they might otherwise have proposed to pay due to the added expense of the termination fee that may become payable in certain circumstances.

We have incurred, and will continue to incur, direct and indirect costs as a result of the Merger.

We have incurred, and will continue to incur, significant costs and expenses, including regulatory costs, fees for professional services and other transaction costs in connection with the Merger, for which we will have received little or no benefit if the Merger is not completed. There are a number of factors beyond our control that could affect the total amount or the timing of these costs and expenses. Many of these fees and costs will be payable by us even if the Merger is not completed and may relate to activities that we would not have undertaken other than to complete the Merger.

Litigation challenging the Merger Agreement may prevent the Merger from being consummated within the expected timeframe or at all.

Lawsuits may be filed against us, our Board of Directors or other parties to the Merger Agreement, challenging our acquisition by Parent or making other claims in connection therewith. Such lawsuits may be brought by our purported stockholders and may seek, among other things, to enjoin consummation of the Merger. One of the conditions to the consummation of the Merger is that the consummation of the Merger is not restrained, made illegal, enjoined or prohibited by any order or legal or regulatory restraint or prohibition of a court of competent jurisdiction or any governmental entity. As such, if the plaintiffs in such potential lawsuits are successful in obtaining an injunction prohibiting the defendants from completing the Merger on the agreed upon terms, then such injunction may prevent the Merger from becoming effective, or from becoming effective within the expected timeframe.

28

THE SPECIAL MEETING

The enclosed proxy is solicited on behalf of the Board of Directors for use at the Special Meeting or at any postponement or adjournment thereof.

Date and Time of the Special Meeting

The Special Meeting will be held virtually via live webcast on      , 2024 at    , Central Time. U.S. Silica Stockholders will be able to attend and vote at the Special Meeting by visiting     .

Purpose of the Special Meeting

At the Special Meeting, we will ask U.S. Silica Stockholders to vote on proposals to: (a) approve the Merger Proposal; (b) approve, on an advisory (nonbinding) basis, the Merger Compensation Proposal; and (c) approve the Adjournment Proposal.

Record Date; Shares Entitled to Vote; Quorum

Only U.S. Silica Stockholders as of the Record Date are entitled to notice of the Special Meeting and to vote at the Special Meeting. Information on how to obtain access to the list of stockholders of record entitled to vote at the Special Meeting during the 10 days before the Special Meeting is available by contacting U.S. Silica’s Corporate Secretary at 24275 Katy Freeway, Suite 600, Katy, Texas 77494. As of the Record Date, there were     Shares outstanding and entitled to vote at the Special Meeting.

The presence at the Special Meeting, in person or by proxy, of holders of record of a majority of the outstanding voting power of the Shares entitled to vote, present in person or represented by proxy, as of the Record Date is considered a quorum for the transaction of business. In the event that a quorum is not present at the Special Meeting, it is expected that the Special Meeting will be adjourned to solicit additional proxies.

Vote Required; Abstentions and Broker Non-Votes

Each U.S. Silica Stockholder will be entitled to one vote for each Share owned as of the close of business on the Record Date.

Assuming the presence of a quorum, the affirmative vote of the holders of a majority of the voting power represented by the outstanding Shares that are entitled to vote thereon is required for the approval of the Merger Proposal. As of the Record Date,   votes constitute a majority of the voting power by the outstanding Shares. The approval of the Merger Proposal by the U.S. Silica Stockholders is a condition to the consummation of the Merger.

Assuming the presence of a quorum, the affirmative vote of a majority of the voting power represented by the Shares present in person or represented by proxy at the Special Meeting and entitled to vote is required to: (i) approve the Merger Compensation Proposal, and (ii) approve the Adjournment Proposal.

If a quorum is present at the Special Meeting, the failure of any U.S. Silica Stockholder of record to: (a) submit a signed proxy card; (b) grant a proxy over the internet or by telephone (in accordance with the instructions detailed in the section of this proxy statement entitled “—Voting at the Special Meeting”); or (c) attend the Special Meeting and vote at the Special Meeting will have the same effect as a vote “AGAINST” the Merger Proposal but will have no effect on the Merger Compensation Proposal or the Adjournment Proposal. If a quorum is present at the Special Meeting, for a U.S. Silica Stockholder who attends the Special Meeting or is represented by proxy and abstains from voting, such abstention will have the same effect as if the U.S. Silica Stockholder voted “AGAINST” the Merger Proposal, the Merger Compensation Proposal and the Adjournment Proposal.

29

Each “broker non-vote” will also count as a vote “AGAINST” the Merger Proposal but will have no effect on the Merger Compensation Proposal or the Adjournment Proposal, because broker non-votes will not be counted as Shares present and entitled to vote with respect to proposals on which the broker has not voted. A so-called “broker non-vote” results when banks, brokers and other nominees return a valid proxy voting upon a matter or matters for which the applicable rules provide discretionary authority but do not vote on a particular proposal because they do not have discretionary authority to vote on the matter and have not received specific voting instructions from the beneficial owner of such Shares. If you do not instruct your bank, broker or other nominee how to vote with respect to any of these items, your bank, broker or other nominee may not vote with respect to the applicable proposal and those votes will be counted as “broker non-votes” because the rules applicable to banks, brokers and other nominees only provide brokers with discretionary authority to vote on proposals that are considered “routine,” and each of the proposals to be presented at the Special Meeting is considered “non-routine.” As a result, no bank, broker or other nominee will be permitted to vote your Shares at the Special Meeting without receiving instructions. Failure to instruct your bank, broker or other nominee on how to vote your Shares will have the same effect as a vote “AGAINST” the Merger Proposal, but will have no effect on the Merger Compensation Proposal or the Adjournment Proposal.

Stock Ownership and Interests of Certain Persons

Shares Held by U.S. Silica’s Directors and Executive Officers

As of the Record Date, our executive officers and directors beneficially owned and were entitled to vote, in the aggregate,    Shares, representing approximately  % of the Shares outstanding on the Record Date.

We currently expect that our executive officers and directors will vote all of their respective Shares (1) “FOR” the Merger Proposal, (2) “FOR” the Merger Compensation Proposal and (3) “FOR” the Adjournment Proposal.

Voting at the Special Meeting

There are four ways to vote if you are a record holder (i.e., you do not hold your Shares through a broker, bank or other nominee):

Although U.S. Silica offers multiple voting methods, U.S. Silica encourages you to vote over the Internet or by telephone as U.S. Silica believes they are the most cost-effective and timely methods. We also recommend that you vote as soon as possible, even if you are currently planning to attend the Special Meeting to ensure your Shares are represented at the Special Meeting if you later decide not to attend the Special Meeting.

The control number located on your proxy card is designed to verify your identity and allow you to submit a proxy for your Shares, and to confirm that your voting instructions have been properly recorded when submitting a proxy over the Internet or by telephone.

Stockholders may generally vote via the internet or by telephone until 11:59 p.m. Eastern Time, on     , 2024, or the Company’s tabulation agent must receive paper proxy cards on or before     , 2024. However, voting deadlines may vary depending on how you hold your Shares, so please carefully review the specific instructions provided on your proxy card or voting instruction form.

30

All Shares represented by properly signed and dated proxies received by the deadline indicated above will be voted at the Special Meeting in accordance with the instructions of the U.S. Silica Stockholder. Properly signed and dated proxies that do not contain voting instructions for one or more specific proposals will be voted with respect to the proposals for which instructions are not provided: (a) “FOR” the Merger Proposal; (b) “FOR” the Merger Compensation Proposal; and (c) “FOR” the Adjournment Proposal. Proxy cards that are returned without a signature will not be counted as present at the Special Meeting and cannot be voted.

If your Shares are registered directly in your name with our transfer agent, Broadridge Corporate Issuer Solutions, Inc., you are considered, with respect to those Shares, the “stockholder of record.” If your Shares are held in a stock brokerage account or by a bank or other record holder, you are considered the “beneficial owner” of Shares held in “street name.” As the beneficial owner, you have the right to direct your broker, bank or other record holder on how to vote your Shares, and you are also invited to attend the Special Meeting. Your broker, bank or other record holder should have enclosed or provided voting instructions for you to use in directing the voting of your Shares.

Revocability of Proxies

Any proxy given by a U.S. Silica Stockholder may be revoked by doing any of the following:

If your Shares are held in the name of a broker, bank or other nominee, you should follow the voting instructions you receive from the holder of record to revoke your proxy or change your vote.

Any adjournment, postponement or other delay of the Special Meeting, including for the purpose of soliciting additional proxies, will allow U.S. Silica Stockholders who have already sent in their proxies to revoke them at any time prior to their use at the Special Meeting, as adjourned, postponed or delayed.

Board of Directors’ Recommendation

The Board, after consulting with its financial advisor and outside legal counsel and reviewing and considering various factors described in “The Merger—Recommendation of Our Board of Directors and Reasons for the Merger,” unanimously (i) determined that the transactions contemplated by the Merger Agreement, including the Merger, are advisable, fair to and in the best interests of U.S. Silica and the U.S. Silica Stockholders, (ii) approved, adopted and declared advisable the Merger Agreement and the transactions contemplated thereby, including the Merger, (iii) directed that the Merger Agreement be submitted to the U.S. Silica Stockholders for approval and adoption and (iv) recommended that the U.S. Silica Stockholders approve and adopt the Merger Agreement.

The Board of Directors unanimously recommends that you vote: (1) “FOR” the Merger Proposal; (2) “FOR” the Merger Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

31

Solicitation of Proxies

The Board of Directors is soliciting your proxy, and U.S. Silica will bear the cost of soliciting proxies. We have engaged Innisfree M&A Incorporated to assist us in the solicitation of proxies, at an estimated cost of $40,000 plus expense reimbursement. Forms of proxies and proxy materials may also be distributed through brokers, custodians and other like parties to the beneficial owners of Shares, in which case these parties will be reimbursed for their reasonable out-of-pocket expenses in accordance with SEC and NYSE regulations. Proxies may also be solicited in person or by telephone, facsimile, electronic mail or other electronic medium by Innisfree or, without additional compensation, by U.S. Silica or U.S. Silica’s directors, officers and employees.

Anticipated Date of Completion of the Merger

Assuming timely satisfaction of necessary closing conditions, including receipt of the approval of the U.S. Silica Stockholders, we currently anticipate that the Merger will be consummated in the third quarter of 2024. However, the exact timing of completion of the Merger cannot be predicted because the Merger is subject to the closing conditions specified in the Merger Agreement and summarized in this proxy statement, many of which are outside of our control.

Appraisal Rights

If the Merger is consummated and certain conditions are met, U.S. Silica Stockholders and beneficial owners who continuously hold Shares through the Effective Time, who do not vote in favor of the Merger Proposal and who properly demand appraisal of their Shares and who do not withdraw their demands or otherwise lose their rights to seek appraisal will be entitled to seek appraisal of their Shares in connection with the Merger under Section 262 of the DGCL. This means that U.S. Silica Stockholders and beneficial owners may be entitled to have their Shares appraised by the Delaware Court of Chancery, and to receive payment in cash of the “fair value” of their Shares, exclusive of any elements of value arising from the accomplishment or expectation of the Merger, together with interest to be paid on the amount determined to be the fair value, if any, as determined by the Delaware Court of Chancery, as described further below. Due to the complexity of the appraisal process, persons who wish to seek appraisal of their Shares are encouraged to seek the advice of legal counsel with respect to the exercise of appraisal rights.

U.S. Silica Stockholders and beneficial owners considering seeking appraisal should be aware that the fair value of their Shares as determined pursuant to Section 262 of the DGCL could be more than, the same as or less than the value of the consideration that they would receive pursuant to the Merger Agreement if they did not seek appraisal of their Shares.

To exercise appraisal rights, U.S. Silica Stockholders or beneficial owners of Shares must: (i) properly deliver a written demand for appraisal to U.S. Silica before the vote is taken on the Merger Proposal; (ii) not submit a proxy or otherwise vote in favor of the Merger Proposal; (iii) continue to hold or beneficially own, as applicable, their Shares upon the making of a demand under clause (a) through the Effective Time (iv) not thereafter withdraw their demand for appraisal or otherwise lose their appraisal rights, in each case in accordance with the DGCL; and (v) otherwise meet the criteria and strictly comply with all other procedures for exercising appraisal rights under the DGCL. Failure to follow exactly the procedures specified under Section 262 of the DGCL may result in the loss of appraisal rights. In addition, the Delaware Court of Chancery will dismiss appraisal proceedings in respect of Shares unless certain stock ownership conditions are satisfied by the U.S. Silica Stockholders and beneficial owners seeking appraisal. The DGCL requirements for exercising appraisal rights are described in further detail in the section entitled “The Merger—Appraisal Rights” beginning on page 32 of this proxy statement, which is qualified in its entirety by Section 262 of the DGCL, the relevant section of the DGCL regarding appraisal rights. A copy of Section 262 of the DGCL is accessible, without subscription or cost, at the following publicly available website: https://delcode.delaware.gov/title8/c001/sc09/index.html#262. If you hold your Shares through a bank, broker, trust, or other nominee and you wish to exercise appraisal rights, you may make a written demand for appraisal in your

32

own name, but you must satisfy the conditions set forth above and your written demand must also reasonably identify the holder of record of the Shares for which demand is made, be accompanied by documentary evidence of your beneficial ownership of stock (such as a brokerage or securities account statement containing such information or a letter from a broker or other record holder of such Shares confirming such information) and a statement that such documentary evidence is a true and correct copy of what it purports to be, and provide an address at which you consent to receive notices given by the Surviving Corporation under Section 262 of the DGCL and to be set forth on the verified listed required by Section 262(f) of the DGCL.

Delisting and Deregistration of Common Stock

If the Merger is completed, the Common Stock will be delisted from the NYSE and deregistered under the Exchange Act, and the Common Stock will no longer be publicly traded.

Other Matters

Pursuant to the DGCL and U.S. Silica’s bylaws (the “Bylaws”), except as otherwise required by law, only the matters set forth in the Notice of Special Meeting may be brought before the Special Meeting.

Householding of Special Meeting Materials

The SEC has adopted rules that permit companies and intermediaries such as brokers to satisfy delivery requirements for proxy statements with respect to two or more stockholders sharing the same address by delivering a single proxy statement addressed to those stockholders. This process, which is commonly referred to as “householding,” potentially provides extra convenience for stockholders and cost savings for companies. U.S. Silica and some brokers household proxy materials, delivering a single proxy statement to multiple stockholders sharing an address, unless contrary instructions have been received from the affected stockholders. Once you have received notice from your broker or U.S. Silica that they or U.S. Silica will be sending householding materials to your address, householding will continue until you are notified otherwise or until you revoke your consent. If you participate in householding and wish to receive a separate Notice of Internet Availability of Proxy Materials or set of these proxy materials, or if you wish to receive separate copies of future Notices, annual reports and proxy statements, please call 1-866-540-7095 or write to: Broadridge Financial Solutions, Inc., Householding Department, 51 Mercedes Way, Edgewood, New York 11717. We will deliver the requested documents to you promptly upon your request. If you hold your Shares through a broker, bank or other nominee, please contact your broker, bank or other nominee to request information about householding.

Questions and Additional Information

If you have any questions concerning the Merger, the Special Meeting or this proxy statement, would like additional copies of this proxy statement or need help voting your Shares, please contact our proxy solicitor:

INNISFREE M&A INCORPORATED

501 Madison Avenue, 20th Floor

New York, New York 10022

Stockholders may call toll-free: (877) 750-8269

Banks and brokers may call collect: (212) 750-5833

33

THE MERGER

This discussion of the Merger is qualified in its entirety by reference to the Merger Agreement, which is attached to this proxy statement as Annex A and incorporated into this proxy statement by reference. You should read the Merger Agreement carefully and in its entirety as it is the legal document that governs the Merger.

Parties Involved in the Merger

U.S. Silica Holdings, Inc.

24275 Katy Freeway

Suite 600

Katy, TX 77494

Telephone (281) 505-6011

U.S. Silica Holdings, Inc. is a global performance materials company and is a member of the Russell 2000. The Company is a leading producer of commercial silica used in the oil and gas industry and in a wide range of industrial applications. Over its 124-year history, U.S. Silica has developed core competencies in mining, processing, logistics and materials science that enable it to produce and cost-effectively deliver over 800 diversified products to customers across our end markets.

U.S. Silica’s business consists of two reportable segments: (i) Oil and Gas Proppants, which includes the SandBox Logistics^™ business and (ii) Industrial & Specialty Products. SandBox Logistics^™ is a state-of-the-art leader in proppant storage, handling and well-site delivery, dedicated to making proppant logistics cleaner, safer and more efficient. The Company has 26 operating mines and processing facilities and two additional exploration stage properties across the United States and is headquartered in Katy, Texas.

Our Common Stock is listed under the symbol “SLCA” on the NYSE.

Our principal executive offices are located at 24275 Katy Freeway, Suite 600, Katy, Texas 77494. For more information about U.S. Silica, please visit our website, www.ussilica.com. Our website address is provided as an inactive textual reference only. The information contained on our website is not incorporated into, and does not form a part of, this proxy statement or any other report or document on file with or furnished to the SEC. See “Where You Can Find More Information” on page 126 of this proxy statement.

Star Holding LLC

c/o Apollo Management X, L.P.

9 West 57th Street

41st Floor

New York, NY 10019

Telephone (212) 515-3200

Parent is a Delaware limited liability company that was formed solely for the purpose of entering into the Merger Agreement and, subject to the terms and conditions thereof, completing the transactions contemplated by the Merger Agreement and the related financing transactions. Parent has not engaged in any business activities other than in connection with the transactions contemplated by the Merger Agreement and related agreements.

34

Parent is an affiliate of the Apollo Funds. The Apollo Funds are managed by affiliates of Apollo. Apollo is a high-growth global alternative asset manager with a focus on three strategies: yield, hybrid and equity. As of December 31, 2023, Apollo had approximately $651 billion assets under management. Apollo’s common shares are listed on the NYSE under the symbol “APO.”

Star Merger Co.

c/o Apollo Management X, L.P.

9 West 57th Street

41st Floor

New York, NY 10019

Telephone (212) 515-3200

Merger Sub is a Delaware corporation and a wholly owned subsidiary of Parent that was formed solely for the purpose of entering into the Merger Agreement and completing the transactions contemplated thereby and the related financing transactions. Merger Sub has not engaged in any business activities other than as incidental to its formation and in connection with the transactions contemplated by the Merger Agreement and related agreements and financing transactions. Upon consummation of the Merger, Merger Sub will merge with and into U.S. Silica, and Merger Sub will cease to exist.

Certain Effects of the Merger on U.S. Silica

Upon the terms and subject to the conditions of the Merger Agreement, at the Effective Time, Merger Sub will merge with and into U.S. Silica, with U.S. Silica continuing as the Surviving Corporation and as a wholly owned subsidiary of Parent. As promptly as practicable following the Effective Time, the Common Stock will be delisted from the NYSE and de-registered under the Exchange Act, and at such time, U.S. Silica will cease to be a publicly traded company and will no longer be obligated to file periodic reports with the SEC. If the Merger is completed, you will not own any shares of the capital stock of the Surviving Corporation, and instead will only be entitled to receive the Merger Consideration described in “—Merger Consideration” on page 36 of this proxy statement or, with respect to any Dissenting Shares, you will only be entitled to receive the “fair value” of your Dissenting Shares as determined by the Delaware Court of Chancery pursuant to an appraisal proceeding as contemplated by Delaware law. The Effective Time will occur at the time the certificate of merger is duly filed with the Secretary of State of the State of Delaware (or at such later time as we, Parent and Merger Sub may agree and specify in the certificate of merger).

Effect on U.S. Silica if the Merger is Not Completed

If the Merger Proposal is not approved by the requisite vote of U.S. Silica Stockholders or if the Merger is not completed for any other reason, you will not receive any payment for your Shares. Instead, we will remain as a public company, the Common Stock will continue to be listed and traded on the NYSE and registered under the Exchange Act and U.S. Silica will be required to continue to file periodic reports with the SEC.

Furthermore, depending on the circumstances that caused the Merger not to be completed, it is possible that the price of our Common Stock will decline significantly. If that were to occur, it is uncertain when, if ever, the price of our Common Stock would return to the price at which it trades as of the date of this proxy statement.

Accordingly, if the Merger is not completed, there can be no assurance as to the future value of your Shares. If the Merger is not completed, the Board will continue to evaluate and review our business operations, properties, dividend policy and capitalization, among other things, make such changes as are deemed appropriate and continue to seek to enhance stockholder value. If the Merger Proposal is not approved by the requisite vote of U.S. Silica Stockholders or if the Merger is not completed for any other reason, there can be no assurance that any other transaction acceptable to the Board will be offered or that our business, prospects or results of operation will not be adversely impacted.

35

In addition, under specified circumstances, we may be required to pay Parent a termination fee, or may be entitled to receive a reverse termination fee from Parent, upon the termination of the Merger Agreement, as described under “The Merger Agreement (The Merger Proposal)—Company Termination Fee, Parent Expense Reimbursement, Reverse Termination Fee” on page 115 of this proxy statement.

Merger Consideration

Common Stock

At the Effective Time, each Share issued and outstanding immediately prior to the Effective Time (other than Excluded Shares) will be converted automatically into the right to receive the Merger Consideration. All Shares converted into the right to receive the Merger Consideration will no longer be outstanding and will automatically be cancelled and cease to exist at the Effective Time, and will thereafter represent only the right to receive the Merger Consideration in cash, without interest, subject to any applicable withholding of taxes.

After the completion of the Merger, under the terms of the Merger Agreement, you will have the right to receive the Merger Consideration, but you will no longer have any rights as a U.S. Silica Stockholder (except that holders of Dissenting Shares will not have the right to receive the Merger Consideration but will instead have the right to receive a payment for the “fair value” of their Dissenting Shares as determined by the Delaware Court of Chancery pursuant to an appraisal proceeding as contemplated by Delaware law, as described in “—Appraisal Rights” on page 75 of this proxy statement).

Company PSUs

At the Effective Time, each Company PSU that is outstanding immediately prior to the Effective Time will vest in full and be cancelled in exchange for the right to receive an amount in cash (subject to any applicable withholding taxes) equal to the product of (x) the number of Shares subject to the Company PSU immediately prior to the Effective Time, multiplied by (y) the Merger Consideration. For purposes of determining the number of Shares subject to a Company PSU immediately prior to the Effective Time: (A) in the case of TSR Company PSUs, the number of Shares will be based on the greater of the target level and the actual level of performance measured as of the Measurement Date and using the value of the Merger Consideration as the “ending stock price” for calculating performance; and (B) in the case of ASF Company PSUs, the number of Shares will be based on (1) actual performance for performance periods completed prior to the Measurement Date, (2) the greater of the target level and the actual level of performance measured as of the Measurement Date for performance periods that are ongoing as of the Measurement Date and (3) target performance in respect of performance periods that have not commenced as of the Measurement Date.

Company RSUs

At the Effective Time, each Company RSU that is outstanding immediately prior to the Effective Time will vest in full and be cancelled in exchange for the right to receive an amount in cash (subject to any applicable withholding taxes) equal to the product of (x) the number of Shares subject to the Company RSU immediately prior to the Effective Time, multiplied by (y) the Merger Consideration.

Company Options

At the Effective Time, each Company Option that is outstanding and unexercised immediately prior to the Effective Time will be cancelled in exchange for the right to receive an amount in cash (subject to any applicable withholding taxes) equal to the product of (x) the excess, if any, of the Merger Consideration over the per Share exercise price of such Company Option, multiplied by (y) the number of Shares covered by such Company Option immediately prior to the Effective Time. If the per Share exercise price of such Company Option equals or exceeds the Merger Consideration, such Company Option shall be cancelled for no consideration.

36

Background of the Merger

The Board and U.S. Silica’s management regularly evaluate U.S. Silica’s business and operations, competitive position, historical performance, future prospects and long-term strategic plan with the goal of maximizing U.S. Silica Stockholder value. As part of these ongoing evaluations, the Board and U.S. Silica’s management have, from time to time and with the assistance of U.S. Silica’s legal and financial advisors, considered various strategic alternatives, including the continued execution of U.S. Silica’s strategy as a stand-alone public company, the possible sale of U.S. Silica to, or combination of U.S. Silica with, a third party, or the possible separation of U.S. Silica’s two business segments, the oil and gas proppants segment and the industrial and specialty products segment.

On October 6, 2021, U.S. Silica announced that it was commencing a review of strategic alternatives for its industrial and specialty products segment. Over the course of the review, the Board considered a range of options with the goal of maximizing U.S. Silica Stockholder value, including the potential sale or separation of the industrial and specialty products segment. As part of the review, U.S. Silica, among other actions, contacted 78 potential bidders, 34 of which entered into confidentiality agreements with U.S. Silica, including Apollo. Eight of the potential bidders, including Apollo, submitted first round preliminary, nonbinding indications of interest. Apollo submitted the only second round preliminary, nonbinding indication of interest, which was structured as a $1.18 billion cash payment to U.S. Silica and an issuance to U.S. Silica of a minority ownership interest in the go-forward industrial and specialty products business controlled by Apollo (which we refer to as the “2021 ISP Apollo Proposal”). All of these confidentiality agreements included a customary standstill provision, but all such provisions had expired before entry into the Merger Agreement.

On June 13, 2022, after extensive evaluation and deliberation, and in consultation with its independent financial and legal advisors, the Board unanimously determined that retaining full ownership of the industrial and specialty products segment represented the best path forward for U.S. Silica and U.S. Silica Stockholders. In making its determination, the Board determined that the 2021 ISP Apollo Proposal failed to provide superior value to U.S. Silica Stockholders as compared to U.S. Silica’s standalone strategic and financial outlook.

On June 23, 2022, a representative of Apollo sent an email to Bryan Shinn, Chief Executive Officer of U.S. Silica, thanking Mr. Shinn for engaging with Apollo during the industrial and specialty products strategic review process. In his email, the representative of Apollo suggested that Apollo and U.S. Silica keep the dialogue between the two companies active and also suggested a future meeting between representatives of the two companies. On June 27, 2022, Mr. Shinn sent an email to the representative of Apollo, thanking Apollo for its interest in the strategic review process and informing the representative of Apollo that U.S. Silica is always looking for opportunities to enhance U.S. Silica Stockholder value. In light of the Board’s decision, however, the discussions concerning the 2021 ISP Apollo Proposal were terminated.

From June 23, 2022, through March 10, 2023, representatives of U.S. Silica and representatives of Apollo engaged in ongoing discussions regarding U.S. Silica. During this period, Mr. Shinn held discussions with Charles Shaver, Chairman of the Board, regarding the ongoing discussions with Apollo, and Mr. Shinn kept the members of the Board apprised of the discussions.

On July 12, 2022, Mr. Shinn, Alan Schultz, U.S. Silica’s Senior Vice President, Strategy, and certain representatives of Apollo met in person in Houston, Texas, and discussed U.S. Silica’s overall business. No potential acquisition transaction was discussed at the meeting.

On November 2, 2022, a representative of Apollo reached out to Mr. Shinn requesting a meeting to discuss U.S. Silica’s business. On January 18, 2023, Mr. Shinn, Mr. Schultz and certain representatives of Apollo met in person in Houston, Texas, and discussed U.S. Silica’s overall business since July, the oil and gas proppants segment and certain related matters. No potential acquisition transaction was discussed at the meeting.

37

On January 19, 2023, a representative of Apollo reached out to Mr. Shinn and Mr. Schultz requesting a follow-up meeting to discuss the oil and gas proppants segment. On February 7, 2023, Mr. Shinn, Mr. Schultz, Derek Ussery, U.S. Silica’s Executive Vice President and President, Oil & Gas, and certain representatives of Apollo met in person in Houston, Texas, and discussed the oil and gas proppants segment. After the conclusion of the meeting, Mr. Shinn, Mr. Schultz, Mr. Ussery and the representatives of Apollo attended a dinner. No potential acquisition transaction was discussed at the meeting or at the dinner.

On February 8, 2023, a representative of Apollo reached out to Mr. Shinn requesting a catch-up call. On February 10, 2023, the representative of Apollo called Mr. Shinn to inform him that Apollo was working toward making an offer to purchase the entire company in the coming weeks. Mr. Shinn responded that, in order for any proposal to be acceptable, Apollo would need to offer an attractive premium to the current market price of U.S. Silica and that he would bring any proposal submitted by Apollo to the Board for its consideration.

On March 13, 2023, Apollo submitted a preliminary, nonbinding indication of interest to acquire 100% of the outstanding equity interests of U.S. Silica in an all-cash transaction at a price of $15.50 per Share (which we refer to as the “2023 Apollo Proposal”). On March 13, 2023, the closing price of the Common Stock was $11.47 per Share. The 2023 Apollo Proposal stated that it was based solely on public information and was subject to Apollo’s satisfactory completion of due diligence. In the 2023 Apollo Proposal, Apollo proposed a “go-shop” period during which U.S. Silica would be permitted to solicit competing bids for a limited period of time following the signing of a transaction. Apollo also, in exchange for its willingness to accept a go-shop period and given the time, effort and cost involved for Apollo to finalize its due diligence, required a period of exclusive negotiations between U.S. Silica and Apollo. Apollo also stated in the 2023 Apollo Proposal that if U.S. Silica refused to proceed with evaluating the transaction on an exclusive basis, Apollo would retract the 2023 Apollo Proposal and would not pursue the transaction further. As a condition to the 2023 Apollo Proposal, Apollo also required U.S. Silica’s consent to engage in confidential discussions with a limited group of third-party investors, to be approved by U.S. Silica, who would partner with Apollo in the potential transaction and make a direct investment in U.S. Silica’s oil and gas proppants segment. The 2023 Apollo Proposal noted that Apollo’s ability to partner with a third party was a key assumption in its offer price. The 2023 Apollo Proposal also requested that U.S. Silica consider abandoning its proposed refinancing of U.S. Silica’s seven-year $950 million senior secured Term Loan B facility due March 23, 2030 (the “Term Loan B Facility”, and such refinancing, the “Refinancing”), and that the proposed purchase price in the 2023 Apollo Proposal would need to be revised downwards in the event U.S. Silica completed the Refinancing. The 2023 Apollo Proposal also noted that the transaction would not be subject to any financing contingency. Mr. Shinn promptly shared the 2023 Apollo Proposal with the Board.

On March 15, 2023, U.S. Silica held a special meeting of the Board by videoconference, during which members of U.S. Silica’s management and representatives of U.S. Silica’s outside legal counsel, Morrison & Foerster LLP (which we refer to as “MoFo”), participated. A representative of MoFo reviewed the Board’s fiduciary duties under Delaware law. Mr. Shinn described his previous interactions with Apollo, including his calls with representatives of Apollo, and reviewed the terms of the 2023 Apollo Proposal with the Board. The Board discussed whether to engage a financial advisor regarding a financial analysis of U.S. Silica in connection with the 2023 Apollo Proposal, and decided to contact Piper Sandler to inquire about possible advice. Piper Sandler was selected by the Board as financial advisor based on its reputation, experience and knowledge of the oil and gas proppants and industrial minerals industries and experience advising companies in mergers and acquisitions. Following discussion, and after taking into consideration the information provided by and discussed with U.S. Silica’s management and representatives of MoFo, the Board directed U.S. Silica’s management to contact Piper Sandler and to call another Board meeting to further discuss the 2023 Apollo Proposal.

On March 16, 2023, a representative of Apollo and Mr. Shinn attended a videoconference call during which Mr. Shinn informed the representative of Apollo that the 2023 Apollo Proposal was being reviewed by the Board and would be further considered at an upcoming Board meeting.

38

On March 28, 2023, U.S. Silica held a special meeting of the Board by videoconference, during which members of U.S. Silica’s management and representatives of Piper Sandler and MoFo participated. A representative of MoFo reviewed the Board’s fiduciary duties under Delaware law. Mr. Shinn reviewed the terms of the 2023 Apollo Proposal with the Board, including Apollo’s requests for an exclusive negotiating period, the proposed go-shop provision and that U.S. Silica abandon the Refinancing. A representative of Piper Sandler reviewed Piper Sandler’s preliminary financial analyses of U.S. Silica. Following discussion, and after taking into consideration the information provided by and discussed with U.S. Silica’s management and U.S. Silica’s advisors, the Board directed U.S. Silica’s management to convey to Apollo that while the 2023 Apollo Proposal was not acceptable, U.S. Silica was nevertheless willing to enter into an exclusivity agreement for 30 days and provide Apollo, subject to the parties entering into a confidentiality agreement, with limited due diligence information and discussions with U.S. Silica’s management to allow Apollo to consider raising its bid. The Board also directed U.S. Silica’s management to make clear to Apollo that U.S. Silica would not enter into a transaction that effectively involved separately agreeing to sell each of its two lines of business to Apollo and its partner, and that all risk associated with Apollo’s partner would need to be borne by Apollo. The Board also determined to proceed with the Refinancing (which was ultimately completed) given the Board’s views regarding the conditionality of the 2023 Apollo Proposal and the Board’s belief that the terms of the Refinancing were favorable and in the best interest of U.S. Silica and U.S. Silica Stockholders. The next day, Mr. Shinn conveyed this message to a representative of Apollo.

On April 3, 2023, Mr. Schultz received a list of high priority business due diligence requests from a representative of Apollo.

On April 4, 2023, Apollo and U.S. Silica entered into a confidentiality agreement (the “2023 Confidentiality Agreement”), which contained a customary standstill provision that would terminate if, among other things, U.S. Silica entered into an agreement providing for the acquisition of U.S. Silica by a third party. The 2023 Confidentiality Agreement also permitted Apollo to engage in discussions with a strategic company referred to herein as Party A, who Apollo was considering partnering with for the oil and gas proppants segment. Also on April 4, 2023, Apollo and U.S. Silica entered into a customary exclusivity agreement (the “2023 Exclusivity Agreement”) that contained a 30-day exclusivity period. The 2023 Exclusivity Agreement permitted U.S. Silica, during the exclusivity period, to engage in discussions and negotiations with, and provide confidential information to, any third-party that submitted an offer that the Board determined would reasonably be expected to lead to a transaction superior to the 2023 Apollo Proposal.

Beginning on April 4, 2023, Apollo and its representatives conducted due diligence on U.S. Silica.

On April 17, 2023, a representative of Apollo called Mr. Shinn to inform him that Party A would no longer be willing to partner with Apollo in the potential acquisition of U.S. Silica due to changes in Party A’s strategic priorities.

On April 19, 2023, representatives of Apollo held due diligence meetings in person in Houston, Texas with senior management of U.S. Silica. During these meetings, a representative of Apollo informed U.S. Silica that Apollo intended to explore the possibility of completing the acquisition of U.S. Silica without a partner. After the conclusion of these meetings, the participants attended a dinner. Neither compensation arrangements nor employment arrangements nor potential roles for existing management in the event of a transaction were discussed at the dinner. The next day, representatives of Apollo held additional due diligence meetings in person in Houston, Texas with senior management of U.S. Silica.

On April 25, 2023, Mr. Shinn and a representative of Apollo held a call during which Mr. Shinn requested that Apollo submit an updated proposal to the Board by May 10, 2023.

39

On May 16, 2023, a representative of Apollo called Mr. Shinn to inform him that, after further review and consideration, Apollo would not be in a position to complete the potential transaction alone and would again be seeking a partner. Mr. Shinn promptly informed the Board of this discussion.

From May 23, 2023, through June 22, 2023, Mr. Shinn and representatives of Apollo exchanged emails and held calls regarding potential third parties for Apollo to partner with in connection with a potential acquisition of U.S. Silica. Mr. Shinn kept Mr. Shaver apprised of these discussions.

On June 23, 2023 and June 30, 2023, a representative of MoFo corresponded with legal counsel of Apollo and granted Apollo permission to contact certain third parties that Apollo believed could be interested in partnering with Apollo in connection with a potential acquisition of U.S. Silica.

On August 15, 2023, a representative of Apollo called Mr. Shinn to inform him that, because Apollo could not find a suitable partner for the potential transaction, Apollo would no longer be pursuing an acquisition of U.S. Silica and that Apollo had stopped work in furtherance thereof.

On August 23, 2023, a representative of a significant equityholder of a strategic company referred to herein as Party B contacted a representative of Piper Sandler regarding the exploration of a potential transaction involving U.S. Silica and Party B, including a combination of the oil and gas proppants segment and Party B’s energy business.

On September 29, 2023, a representative of Party B and a representative of Piper Sandler had a follow-up discussion regarding the same.

On November 8, 2023, Mr. Shaver and representatives of certain significant equityholders of Party B met in person in New York, New York regarding the same.

On November 30, 2023, U.S. Silica held a special meeting of the Board by videoconference, during which members of U.S. Silica’s management and representatives of MoFo participated. The Board and management discussed, among other items, general corporate strategy, strategy for the industrial and specialty products segment and strategy for the oil and gas proppants segment. The Board and management also discussed the potential separation of the industrial and specialty products segment and the oil and gas proppants segment as well as initial separation considerations. After discussion, the Board authorized U.S. Silica’s management to begin undertaking work to assist the Board with exploring the possibility of separating the industrial and specialty products segment and the oil and gas proppants segment in the future.

On January 16, 2024, Mr. Shinn and Mr. Schultz and representatives of Piper Sandler attended a meeting in Houston, Texas with representatives of Party B, certain of its significant equityholders and its financial advisor. During the meeting, the parties discussed various alternatives for the combination of the oil and gas proppants segment and Party B’s energy business, including the form of consideration to be paid to U.S. Silica. Mr. Shinn stated that the Board would view more favorably a transaction where a significant amount of the consideration would be in cash as opposed to a transaction where a significant amount of the consideration would be in equity. The parties also discussed the possibility of Party B and U.S. Silica entering into a mutual confidentiality agreement under which Party B and U.S. Silica would receive confidential information, which would allow Party B to refine its analysis and submit a proposal to U.S. Silica.

On January 17, 2024, the executive committee of the Board, which is a standing committee of the Board (i.e., not one formed in connection with any proposed transaction or U.S. Silica’s evaluation of strategic alternatives), held a meeting by videoconference and discussed the potential transaction with Party B, including the minimum cash consideration that would be necessary for the transaction to be attractive.

On January 18, 2024, a representative of a significant equityholder of Party B contacted a representative of Piper Sandler regarding its and Party B’s interest in engaging in discussions with Piper Sandler’s debt capital

40

markets desk regarding potential sources of financing for Party B as it pursued a combination of its energy business and the oil and gas proppants segment. Promptly thereafter, such representative of Piper Sandler informed senior management of U.S. Silica of Party B’s request.

On January 28, 2024, a representative of Party B provided Piper Sandler with Party B’s initial due diligence request list.

On February 1, 2024, U.S. Silica entered into a mutual confidentiality agreement with Party B, which contained a customary standstill provision that permitted Party B and U.S. Silica (as applicable) to make confidential proposals or offers to acquire U.S. Silica or Party B (as applicable) unless any such proposals or offers would reasonably be expected to require any person to make a public announcement regarding such proposals or offers. On that same day, U.S. Silica also entered into a customary standstill agreement with certain significant equityholders of Party B, which permitted such parties to make confidential proposals or offers to acquire U.S. Silica unless any such proposals or offers would reasonably be expected to require any person to make a public announcement regarding such proposals or offers.

Beginning on February 1, 2024, and continuing through April 16, 2024, Party B and its representatives conducted due diligence on the oil and gas proppants segment, and U.S. Silica and its representatives reviewed the limited materials provided by Party B regarding Party B’s energy business.

On February 7, 2024, a representative of Apollo called Mr. Shinn to invite him to dinner. On February 13, 2024, at the dinner, the representative of Apollo told Mr. Shinn that Apollo had started new efforts in furtherance of a potential acquisition transaction and that Apollo would be submitting a preliminary, nonbinding indication of interest to acquire U.S. Silica the next day. Mr. Shinn responded that he would bring any proposal submitted by Apollo to the Board for its consideration. Neither compensation arrangements nor employment arrangements nor potential roles for existing management in the event of a transaction were discussed at the dinner.

On February 14, 2024, Apollo submitted a preliminary, nonbinding indication of interest to acquire 100% of the outstanding equity interests of U.S. Silica in an all-cash transaction at a price of $13.50 per Share (which we refer to as the “2024 Apollo Proposal”). The $13.50 price per Share represented a 30.9% premium relative to the $10.31 closing price of the Common Stock on February 13, 2024, the last trading day prior to the submission of the 2024 Apollo Proposal. The 2024 Apollo Proposal included certain “highly confident” letters from potential debt financing sources, which letters stated that such debt financing sources were highly confident in their ability to raise the debt financing necessary to complete the potential acquisition. The 2024 Apollo Proposal was subject to Apollo’s satisfactory completion of due diligence. In the 2024 Apollo Proposal, Apollo proposed a “go-shop” period during which U.S. Silica would be permitted to solicit competing bids for a limited period of time following the signing of a transaction. Apollo also, in exchange for its willingness to accept a go-shop period and given the time, effort and cost involved for Apollo to finalize its due diligence, required a period of exclusive negotiations between U.S. Silica and Apollo. Apollo also stated in the 2024 Apollo Proposal that if U.S. Silica refused to proceed with evaluating the transaction on an exclusive basis, Apollo would retract the 2024 Apollo Proposal and would not pursue the transaction further. Unlike the 2023 Apollo Proposal, the 2024 Apollo Proposal specifically stated that Apollo did not require a third-party partner or any additional equity capital to complete the potential transaction and did not request permission to discuss the potential transaction with potential third-party partners. The 2024 Apollo Proposal also noted that the potential transaction would not be subject to any financing contingency and that, to the extent Apollo identified additional sources of value in its due diligence investigations that were tangible and underwritable, but are not apparent from the information it reviewed prior to submitting the proposal, it would be prepared to improve its offer. Mr. Shinn promptly shared the 2024 Apollo Proposal with the Board.

During the period between February 15, 2024, and February 19, 2024, the executive committee of the Board discussed the 2024 Apollo Proposal and determined that the offer price was not high enough to warrant U.S. Silica meaningfully engaging with Apollo or providing exclusivity. However, the executive committee of the

41

Board concluded that U.S. Silica was willing to provide Apollo, subject to the parties entering into a confidentiality agreement, with limited business due diligence information and discussions with U.S. Silica’s management to allow Apollo to consider raising its bid.

On February 20, 2024, a representative of U.S. Silica sent a draft confidentiality agreement to a representative of Apollo (the “2024 Confidentiality Agreement”). The 2024 Confidentiality Agreement was substantially in the form of the 2023 Confidentiality Agreement, but removed Apollo’s ability to engage in discussions with Party A (consistent with the new structure of the 2024 Apollo Proposal) and removed all references to an exclusivity agreement.

On February 21, 2024, a representative of Apollo sent a revised draft of the 2024 Confidentiality Agreement to a representative of U.S. Silica, which draft reinserted the references to an exclusivity agreement.

On February 23, 2024, Mr. Shinn called a representative of Apollo and reiterated that U.S. Silica would not, at this time, be willing to grant exclusivity to Apollo and that Apollo would need to substantially improve its offer before the Board would consider exclusivity.

On February 24, 2024, Mr. Schultz received a list of high priority business due diligence requests from a representative of Apollo.

On February 25, 2024, a representative of Apollo sent a revised draft of the 2024 Confidentiality Agreement to a representative of U.S. Silica, which draft removed all references to an exclusivity agreement. The 2024 Confidentiality Agreement contained a customary standstill provision that would terminate if, among other things, U.S. Silica entered into an agreement providing for the acquisition of U.S. Silica by a third party.

On February 26, 2024, Apollo and U.S. Silica entered into the 2024 Confidentiality Agreement, which did not contain references to an exclusivity agreement.

Also on February 26, 2024, Party B submitted a preliminary, nonbinding indication of interest to combine Party B’s energy business and the oil and gas proppants segment (the “February Party B Proposal”). Pursuant to the February Party B Proposal, U.S. Silica would receive total consideration of $450 million in cash, $50 million in seller financing and 30% of the equity interests in the entity resulting from the combination of Party B’s energy business and the oil and gas proppants segment (“Combined EnergyCo”), which Party B valued at $400 million. The February Party B Proposal was contingent on U.S. Silica distributing its equity interests in Combined EnergyCo to U.S. Silica Stockholders. Mr. Shinn promptly shared the February Party B Proposal with the Board.

On February 27, 2024, a representative of Piper Sandler informed a representative of Party B that U.S. Silica expected at least $700 million in cash consideration payable to U.S. Silica in connection with the combination of Party B’s energy business and the oil and gas proppants segment.

Beginning on February 27, 2024, and continuing through April 26, 2024, Apollo and its representatives conducted due diligence on U.S. Silica.

On March 5, 2024, Piper Sandler’s debt capital markets team provided representatives of Party B and certain of its significant equityholders a draft engagement letter for purposes of outlining potential terms of a debt financing. No engagement letter was subsequently executed.

On March 7, 2024, Mr. Shinn, Mr. Schultz, Mr. Ussery, Zach Carusona, Executive Vice President and President, industrial and specialty products segment of U.S. Silica, and certain representatives of Apollo attended a dinner in Houston, Texas, and discussed at a high level the due diligence areas that would be covered during management meetings the next day. Neither compensation arrangements nor employment arrangements nor potential roles for existing management in the event of a transaction were discussed at the dinner.

42

On March 8, 2024, representatives of Apollo held due diligence meetings in person in Houston, Texas with senior management of U.S. Silica. During the meetings, Mr. Shinn informed Apollo that U.S. Silica expected Apollo to submit an updated proposal.

On March 12, 2024, Mr. Shinn and Mr. Schultz attended a videoconference with representatives of certain of Party B’s equityholders, during which Mr. Shinn emphasized that the cash component of the February Party B Proposal needed to be higher.

On March 18, 2024, a representative of Apollo called Mr. Shinn to preview Apollo’s revised proposal, including that Apollo intended to increase the price per Share to $14.30 per Share.

Later that same day, Apollo submitted a revised preliminary, nonbinding indication of interest to acquire 100% of the outstanding equity interests of U.S. Silica in an all-cash transaction at a price of $14.30 per Share (which we refer to as the “Updated 2024 Apollo Proposal”), which represented a 5.9% increase in the 2024 Apollo Proposal and a 38.7% premium relative to the $10.31 closing price of the Common Stock on February 13, 2024, the last trading day prior to the submission of the 2024 Apollo Proposal. On March 18, 2024, the closing price of the Common Stock was $12.73 per Share. The Updated 2024 Apollo Proposal provided that, although Apollo was increasing the offer price, Apollo had identified certain negative diligence findings over the preceding weeks which had negatively affected its valuation of U.S. Silica. Similar to the 2024 Apollo Proposal, the Updated 2024 Apollo Proposal also included certain “highly confident” letters from potential debt financing sources, stated that it was subject to Apollo’s satisfactory completion of confirmatory due diligence, and offered a “go-shop” period in exchange for a twenty-five-day period of exclusive negotiations between U.S. Silica and Apollo. Mr. Shinn promptly shared the Updated 2024 Apollo Proposal with the Board.

On March 18, 2024, Mr. Shinn called a representative of Apollo regarding the Updated 2024 Apollo Proposal. Mr. Shinn provided U.S. Silica’s views on certain aspects of the negative due diligence findings described in the proposal and noted that the proposal neglected to include certain other, positive findings, including that U.S. Silica had paid off a significant amount of debt since the 2023 Apollo Proposal. The representative of Apollo acknowledged the reduction of debt but further clarified to Mr. Shinn that such debt reduction was already fully factored into the Updated 2024 Apollo Proposal. The representative of Apollo further clarified that the 2023 Apollo Proposal contemplated a transaction where Party A would acquire the oil and gas proppants segment at a significant price that reflected the synergies that Party A would be able to realize from that acquisition. Since Party A was no longer actively considering an acquisition of the oil and gas proppants segment and Apollo was now acting as a standalone bidder that would not be able to realize such synergies, the price that Apollo was willing to offer was lower. Mr. Shinn also informed the representative of Apollo that the Board would be considering Apollo’s proposal at an upcoming Board meeting.

On March 22, 2024, Piper Sandler’s debt capital markets team provided representatives of Party B and certain of its significant equityholders with an illustrative term sheet outlining potential terms of a debt financing.

On March 27, 2024, Party B submitted an updated preliminary, nonbinding indication of interest to combine Party B’s energy business and the oil and gas proppants segment (the “March Party B Proposal”). Pursuant to the March Party B Proposal, U.S. Silica would receive total consideration of $700 million in cash ($650 million of which would be financed through third-party debt to be raised by Combined EnergyCo and $50 million of which would come from Party B) and 12.5% of the equity interests in Combined EnergyCo, which Party B valued at $200 million. The March Party B Proposal was again contingent on U.S. Silica distributing its equity interests in Combined EnergyCo to U.S. Silica Stockholders. Mr. Shinn promptly shared the March Party B Proposal with the Board.

On March 28, 2024, U.S. Silica held a special meeting of the Board by videoconference, during which members of U.S. Silica’s management participated. At the meeting, a representative of U.S. Silica reviewed the Board’s fiduciary duties under Delaware law. Thereafter, the Board and U.S. Silica’s management discussed U.S.

43

Silica’s business outlook and U.S. Silica’s stock price performance, including their shared belief that the public equity markets value U.S. Silica’s stock at a lower multiple as if it were a pure oil and gas company and ascribe minimal value to the industrial and specialty products segment. The Board and U.S. Silica’s management also evaluated U.S. Silica’s strategic alternatives other than the transactions contemplated by the Updated 2024 Apollo Proposal and the March Party B Proposal, including the execution of U.S. Silica’s stand-alone business plan as a publicly traded company, undertaking industrial minerals acquisitions without separating the industrial and specialty products segment, undertaking industrial minerals acquisitions and thereafter separating the industrial and specialty products segment, and the sale of the industrial and specialty products segment. The Board and U.S. Silica’s management considered the possible increase in U.S. Silica’s value that could be achieved upon the successful execution of those alternatives relative to the value proposed in the Updated 2024 Apollo Proposal or the March Party B Proposal, as well as the risks related to U.S. Silica’s ability to execute successfully on those alternatives and proposals. The Board and U.S. Silica’s management discussed the key terms of the February Party B Proposal and the March Party B Proposal, including the ability of the Combined EnergyCo to secure the necessary debt financing and that Party B had not committed to fill any shortfalls in debt financing. The Board and U.S. Silica’s management also expressed concerns about the value of the equity interest in Combined EnergyCo, as U.S. Silica Stockholders would hold a minority equity interest in a controlled company with a small public float that would also have limited financial flexibility. The Board and U.S. Silica’s management also discussed the key terms of the Updated 2024 Apollo Proposal. Following discussion, and after taking into consideration the information provided by and discussed with U.S. Silica’s management, the Board determined to direct Piper Sandler to conduct further analysis of U.S. Silica’s strategic options, including in respect of the industrial and specialty products segment.

On April 4, 2024, U.S. Silica held a special meeting of the Board by videoconference, during which members of U.S. Silica’s management and representatives of Piper Sandler and MoFo participated. At the meeting, representatives of Piper Sandler provided an overview of Piper Sandler’s analysis of the industrial and specialty products segment, with the assumption that U.S. Silica sold the oil and gas proppants segment and used the proceeds from that sale under certain illustrative scenarios. Representatives of Piper Sandler noted that any acquisitions undertaken with such proceeds would need significant synergies to be accretive and that the pool of highly synergistic acquisition targets was relatively small, with most targets being private companies that were not currently for sale, and, as a result, Piper Sandler believed, based on its professional judgment and experience, there was significant execution risk around growth through acquisitions. The Board, U.S. Silica’s management and U.S. Silica’s advisors again considered the possible increase in U.S. Silica’s value that could be achieved upon the successful execution of certain strategic alternatives relative to the value proposed in the Updated 2024 Apollo Proposal or the March Party B Proposal, as well as the risks related to U.S. Silica’s ability to execute successfully on those alternatives and proposals. The Board, U.S. Silica’s management and U.S. Silica’s advisors also discussed the March Party B Proposal, including that the value of the equity consideration in the March Party B Proposal was likely substantially lower than the value that Party B ascribed to it. Following discussion, and after taking into consideration the information provided by and discussed with U.S. Silica’s management and U.S. Silica’s advisors, the Board determined to schedule another meeting of the Board to further discuss responses to Apollo and Party B.

On April 9, 2024, U.S. Silica held a special meeting of the Board by videoconference, during which members of U.S. Silica’s management and representatives of Piper Sandler and MoFo participated. The Board, U.S. Silica’s management and U.S. Silica’s advisors again reviewed the strategic alternatives that had been discussed at the Board’s March 28 and April 4 meetings. The Board, U.S. Silica’s management and U.S. Silica’s advisors then discussed the Updated 2024 Apollo Proposal and the March Party B Proposal, noting that the March Party B Proposal contained significantly more execution risk for several reasons, including the complexity of the transaction, that debt financing had not been secured, that Party B had not committed to funding any shortfall in debt financing and that Party B and U.S. Silica would need to conduct a significant amount of mutual due diligence given the asset carveout complexity of the transaction and U.S. Silica’s need to fully understand the value of the equity consideration that would be distributed to U.S. Silica Stockholders. The Board, U.S. Silica’s management and U.S. Silica’s advisors also expressed concerns about the value of the equity interest in

44

Combined EnergyCo for the reasons previously discussed. The Board, U.S. Silica’s management and U.S. Silica’s advisors also discussed that the transaction contemplated by the Updated 2024 Apollo Proposal was less complex than the transaction contemplated by the March Party B Proposal and that Apollo committed in the Updated 2024 Apollo Proposal to signing definitive agreements relatively quickly, had provided “highly confident” letters from credible financial institutions and had committed to funding the entire equity component of the financing, and had conducted a significant amount of due diligence to date. Following discussion, and after taking into consideration the information provided by and discussed with U.S. Silica’s management and U.S. Silica’s advisors, the Board concluded that Apollo would need to meaningfully increase its offer price from the offer price proposed in the Updated 2024 Apollo Proposal in order for U.S. Silica to continue its engagement regarding a potential transaction. The Board also directed U.S. Silica’s management to prepare a responsive letter to Party B in order to obtain clarity on certain critical unresolved open points, including whether Party B would fund any shortfall in the debt financing and the valuation ascribed to the equity consideration outlined in the March Party B Proposal. The Board also discussed that U.S. Silica should proceed with Apollo and Party B in parallel, but that U.S. Silica may need to grant Apollo exclusivity if Apollo were to offer a sufficiently improved offer price. The Board then discussed the potential benefits of forming a Transaction Committee (as a committee of convenience, to be able to respond nimbly to the day-to-day aspects of negotiations) to provide regular input and direction to U.S. Silica’s management and U.S. Silica’s advisors. Following discussion, the Board concluded that it would be in the best interest of U.S. Silica and U.S. Silica Stockholders to form a Transaction Committee (as a committee of convenience); however, the Transaction Committee was not empowered to make recommendations or decisions regarding whether to move forward with any potential transaction. The Transaction Committee initially consisted of Simon Bates, Peter Bernard, Diane Duren and Mr. Shinn. Such directors were selected for the Transaction Committee based on their relevant experience and qualifications to serve on such a committee. The decision to form the Transaction Committee was not the result of any actual or potential conflict of interest of any member of the Board. The Board then directed the Transaction Committee to meet to preliminarily determine a counteroffer to present to Apollo.

On April 11, 2024, the Transaction Committee met via videoconference, during which members of U.S. Silica’s management and representatives of MoFo participated. The members of the Transaction Committee discussed various potential prices per Share to present to Apollo as a counterproposal.

On April 12, 2024, Mr. Shinn and a representative of Apollo held a call and discussed U.S. Silica’s valuation and Apollo’s expectation that U.S. Silica respond to the Updated 2024 Apollo Proposal by no later than the morning of April 15, 2024. Mr. Shinn told the representative of Apollo that the Board was holding a special meeting the following day and that U.S. Silica would respond shortly thereafter.

On April 13, 2024, U.S. Silica held a special meeting of the Board by videoconference, during which members of U.S. Silica’s management and representatives of Piper Sandler and MoFo participated. At the meeting, a representative of MoFo reviewed the Board’s fiduciary duties under Delaware law. The Board, U.S. Silica’s management and U.S. Silica’s advisors again reviewed U.S. Silica’s strategic alternatives (including the March Party B Proposal), the possible increase in U.S. Silica’s value that could be achieved upon the successful execution of those alternatives relative to the value proposed in the Updated 2024 Apollo Proposal and the risks related to U.S. Silica’s ability to execute successfully on those alternatives and the Updated 2024 Apollo Proposal. Following discussion, and after taking into consideration the information provided by and discussed with U.S. Silica’s management and U.S. Silica’s advisors, the Board determined to present a counteroffer of $16.25 per Share. The Board directed U.S. Silica’s management to present the counteroffer to Apollo. Later that day, Mr. Shinn called a representative of Apollo and presented the counteroffer.

On April 14, 2024, a representative of Apollo called Mr. Shinn and presented a counteroffer of $15.25 per Share, informing Mr. Shinn that this was Apollo’s best and final offer. Later that day, Mr. Shinn and Mr. Shaver held a call to discuss the negotiations with Apollo, including that the representative of Apollo had stated that $15.25 was Apollo’s best and final offer. Mr. Shinn and Mr. Shaver determined to respond with a counteroffer of $15.75 per Share. Mr. Shinn and Mr. Shaver also discussed that U.S. Silica’s best and final offer would be

45

$15.50 per Share. Mr. Shinn then called the representative of Apollo and presented the counteroffer of $15.75 per Share. Following discussion, Mr. Shinn and the representative of Apollo agreed in principle on a purchase price of $15.50 per Share, subject to the Board’s approval, completion of due diligence and negotiation of mutually acceptable definitive documentation. Also on April 14, 2024, Apollo submitted a letter confirming the preliminary, nonbinding offer price of $15.50 per Share (which we refer to as the “Final Apollo Proposal”), subject to completion of due diligence and negotiation of mutually acceptable definitive documentation. On April 12, 2024, the last full trading day prior to April 14, the closing price of the Common Stock was $12.90 per Share. The $15.50 price per Share represented a 14.8% increase in the 2024 Apollo Proposal and a 50.3% premium relative to the $10.31 closing price of the Common Stock on February 13, 2024, the last trading day prior to the submission of the 2024 Apollo Proposal. Mr. Shinn promptly sent an email to the members of the Board regarding the negotiations with Apollo, including the agreement in principle on a purchase price of $15.50 per Share.

On April 15, 2024, representatives of MoFo and representatives of Apollo’s outside legal counsel, Wachtell, Lipton, Rosen & Katz (which we refer to as “Wachtell Lipton”), held an introductory videoconference call and discussed, among other items, the process to signing definitive agreements by no later than April 26, 2024, which U.S. Silica and Apollo had agreed to target for signing a definitive agreement, Apollo’s contemplated financing and Apollo’s request for exclusivity. Later that day, a representative of Wachtell Lipton sent a draft exclusivity agreement to a representative of MoFo (the “2024 Exclusivity Agreement”). The 2024 Exclusivity Agreement was substantially the same as the 2023 Exclusivity Agreement, and contained a period of exclusivity through April 26, 2024, subject to automatic extension if the parties were still actively working in good faith in furtherance of the transaction. The 2024 Exclusivity Agreement permitted U.S. Silica, during the exclusivity period, to engage in discussions and negotiations with, and provide confidential information to, any third-party that submitted an offer that the Board determined would reasonably be expected to lead to a transaction superior to the Final Apollo Proposal. That same day, Mr. Schultz received a list of due diligence requests from a representative of Apollo.

Also on April 15, 2024, Apollo and its representatives were provided with access to an electronic data room (the “Data Room”) containing information from U.S. Silica that was responsive to the due diligence requests submitted by Apollo to Mr. Schultz earlier that day. The due diligence information made available to Apollo and its representatives in the Data Room continued to be supplemented and updated by U.S. Silica and its representatives in response to due diligence requests from Apollo and its representatives during the period from April 15, 2024 through April 26, 2024.

On April 16, 2024, a representative of U.S. Silica sent a draft of the 2024 Exclusivity Agreement to the members of the Board, none of which objected to U.S. Silica entering into the 2024 Exclusivity Agreement. Later that day, Apollo and U.S. Silica entered into the 2024 Exclusivity Agreement.

On April 17, 2024, a representative of U.S. Silica sent to the Board a relationship disclosure provided by Piper Sandler regarding Piper Sandler’s relationships with U.S. Silica, Apollo and their respective affiliates from January 1, 2020 through April 10, 2023, which summary had previously been provided by Piper Sandler in connection with the Board’s consideration of the 2023 Apollo Proposal.

On April 18, 2024, representatives of Wachtell Lipton sent an initial draft of the Merger Agreement to representatives of MoFo. Among other terms, the draft Merger Agreement included: (i) a go-shop period of 20 days, (ii) a termination fee payable to Apollo equal to 2% of U.S. Silica’s equity value based on the Merger Consideration if U.S. Silica terminated the Merger Agreement to enter into a definitive agreement in respect of a superior proposal prior to the end of the go-shop period, (iii) a termination fee payable to Apollo equal to 4% of U.S. Silica’s equity value based on the Merger Consideration if U.S. Silica terminated the Merger Agreement to enter into a definitive agreement in respect of a superior proposal after the conclusion of the go-shop period and under certain other circumstances, and (iv) a termination fee payable to U.S. Silica equal to 5.5% of U.S. Silica’s equity value based on the Merger Consideration if the Merger Agreement was terminated under certain circumstances.

46

Also on April 18, 2024, U.S. Silica held a special meeting of the Board by videoconference, during which members of U.S. Silica’s management and representatives of Piper Sandler and MoFo participated. At the meeting, a representative of MoFo reviewed the Board’s fiduciary duties under Delaware law. U.S. Silica’s management reviewed again with the Board the Financial Projections, as further described in the section of this proxy statement titled “—Certain Unaudited Financial Projections.” The Financial Projections had been reviewed by the Board on a number of prior occasions and were the same projections used in connection with the repricing of the Term Loan B Facility, which repricing had been completed on March 25, 2024. The Board then approved the Financial Projections for use by Piper Sandler in connection with performing its financial analyses summarized under the section of this proxy statement titled “—Opinion of Piper Sandler.” A representative of MoFo then reviewed with the Board Piper Sandler’s relationship disclosure regarding Piper Sandler’s relationships with U.S. Silica, Apollo and their respective affiliates, which provided that from January 1, 2020 through April 10, 2023, Piper Sandler had received approximately $12.7 million in investment banking fees from Apollo-related parties in connection with nine separate transactions for six Apollo-related parties and that Piper Sandler had been mandated as a joint book-running manager on the contemplated initial public offering of an Apollo affiliate that ultimately was withdrawn in 2023. After discussion, the Board determined that no existing or prior relationship with U.S. Silica, Apollo or their respective affiliates would impact Piper Sandler’s ability to act in an independent and disinterested manner in rendering its services to the Board in connection with the potential transaction. Representatives of MoFo outlined to the Board certain key terms in the initial draft of the Merger Agreement, including the proposed 20 day go-shop period and 2% termination fee during the go-shop period. The Board, U.S. Silica’s management and U.S. Silica’s advisors discussed go-shop provisions generally and the Board’s fiduciary duties, as well as how a go-shop provision gives U.S. Silica certainty of an acceptable transaction and at the same time allows U.S. Silica to run a broad market check after signing the Merger Agreement. The Board discussed the certainty that the Final Apollo Proposal would give to U.S. Silica Stockholders and the benefits of the ability to solicit higher offers during the go-shop period, but reiterated that only a go-shop period of no less than 45 days would be acceptable so that U.S. Silica would have substantial time to solicit other bidders. A representative of Piper Sandler provided the Board with an overview of the go-shop process, including timing considerations, potential bidders, and materials to be provided to potential bidders in the process. At the conclusion of the meeting, the Board discussed whether to authorize U.S. Silica’s management to engage, for the first time, in discussions with Apollo regarding the post-transaction management structure and compensation, with the Board ultimately determining that U.S. Silica’s management should not engage in such discussions until after signing, and the Board directed management not to engage in such discussions.

On April 21, 2024, a representative of MoFo sent a revised draft of the Merger Agreement to representatives of Wachtell Lipton. Among other terms, the revised agreement included: (i) a go-shop period of 60 days, with an extended period for any potential bidder with whom U.S. Silica was in negotiations at the conclusion of the go-shop period and for which the Board has determined could reasonably be expected to lead to a superior proposal, (ii) a termination fee payable to Apollo equal to 0.85% of U.S. Silica’s equity value based on the Merger Consideration if U.S. Silica terminated the Merger Agreement to enter into a definitive agreement in respect of a superior proposal prior to the end of the go-shop period, (iii) a termination fee payable to Apollo equal to 2.25% of U.S. Silica’s equity value based on the Merger Consideration if U.S. Silica terminated the Merger Agreement to enter into a definitive agreement in respect of a superior proposal after the conclusion of the go-shop period and under certain other circumstances, and (iv) a termination fee payable to U.S. Silica equal to 8% of U.S. Silica’s equity value based on the Merger Consideration if the Merger Agreement was terminated under certain circumstances.

Between April 21, 2024, and April 26, 2024, representatives of Wachtell Lipton and MoFo continued to exchange revised drafts of the Merger Agreement, and the parties and their representatives continued to discuss the potential terms of the Merger Agreement.

On April 23, 2024, a representative of MoFo sent representatives of Wachtell Lipton an initial draft of the confidential disclosure schedule to the Merger Agreement. That same day, a representative of Wachtell Lipton

47

sent representatives of MoFo initial drafts of Apollo’s equity commitment letter and limited guarantee and a representative of Apollo’s outside financing counsel, Paul, Weiss, Rifkind, Wharton & Garrison LLP (which we refer to as “Paul, Weiss”), sent representatives of MoFo initial drafts of Apollo’s debt commitment letters. Between April 23, 2024, and April 26, 2024, representatives of Wachtell Lipton and Paul, Weiss, on the one hand, and representatives of MoFo, on the other hand, continued to exchange revised drafts of the equity commitment letter, limited guarantee and debt commitment letters, as applicable, and the parties and their representatives continued to discuss the potential terms of each.

On April 24, 2024, U.S. Silica held a special meeting of the Board by videoconference, during which members of U.S. Silica’s management and representatives of Piper Sandler and MoFo participated. A representative of Piper Sandler presented Piper Sandler’s financial analysis with respect to the Merger Consideration of $15.50 per Share reflected in the Final Apollo Proposal. The Board asked questions regarding the financial analysis. A representative of Piper Sandler then confirmed that, if an opinion were requested by the Board, Piper Sandler would be able to render an opinion as of that date that the Merger Consideration was fair, from a financial point of view, to the holders of Shares (other than Excluded Shares). A representative of MoFo reviewed the Board’s fiduciary duties under Delaware law. A representative of MoFo then guided the Board in a discussion and review of the draft Merger Agreement and related transaction documents (which had been provided to the Board prior to the meeting), including the equity commitment letter and limited guarantee. A representative of MoFo discussed with the Board certain key terms of such documents, including the interim operating covenants, financing covenants, go-shop provision, regulatory efforts covenant, conditions to closing, termination provisions and termination fees. A representative of MoFo then discussed with the Board the material open issues in the Merger Agreement, including the length of the go-shop period and the amounts of the termination fees. Following discussion, and after taking into consideration the information provided by and discussed with U.S. Silica’s management and U.S. Silica’s advisors, the Board directed U.S. Silica’s management and U.S. Silica’s advisors to respond to Apollo’s latest proposals on such items, including that the Board was unwilling to approve a transaction with less than a 45-day go-shop period.

On April 25, 2024, Mr. Shinn and a representative of Apollo held a call to discuss the length of the go-shop period and the amounts of the termination fees payable by U.S. Silica. On the call, the representative of Apollo indicated that Apollo would be willing to accept a 45 day go-shop period and proposed a termination fee payable to Apollo equal to 1.65% of U.S. Silica’s equity value based on the Merger Consideration if U.S. Silica terminated the Merger Agreement to enter into a definitive agreement in respect of a superior proposal prior to the end of the go-shop period, a termination fee payable to Apollo equal to 3.3% of U.S. Silica’s equity value based on the Merger Consideration if U.S. Silica terminated the Merger Agreement to enter into a definitive agreement in respect of a superior proposal after the end of the go-shop period and under certain other circumstances and a termination fee payable to U.S. Silica equal to 6.9% of U.S. Silica’s equity value based on the Merger Consideration if the Merger Agreement was terminated under certain circumstances. Through the rest of the day on April 25, 2024, until the special meeting of the Board during the early morning of April 26, 2024, representatives of MoFo and Wachtell Lipton worked to finalize the definitive transaction documents, and representatives of MoFo and Paul, Weiss worked to finalize the debt commitment letters, with all remaining open points resolved prior to the Board meeting. Also during this period, a representative of U.S. Silica continued to update the members of the Board with respect to the resolution of the open points in the transaction documents.

During the morning of April 26, 2024, U.S. Silica held a special meeting of the Board by videoconference, during which members of U.S. Silica’s management and representatives of Piper Sandler and MoFo participated. Prior to the meeting, all final transaction documents were provided to the Board, including the Merger Agreement, equity commitment letter, debt commitment letters, limited guarantee, confidential disclosure schedules and surviving corporation charter. A representative of MoFo reviewed the Board’s fiduciary duties under Delaware law. A representative of MoFo then discussed the key terms of the proposed transaction, including the resolution of the open points from the April 24 Board meeting (of which the Board had also received updates throughout the course of April 25), including that the go-shop period would be 45 days. Members of the Board then reviewed the updated relationship disclosure from Piper Sandler regarding Piper

48

Sandler’s relationships with U.S. Silica, Apollo and their respective affiliates, which was consistent with the relationship disclosure discussed at the Board’s April 18 meeting and which provided that, from January 1, 2021, through April 24, 2024, Piper Sandler had received approximately $3.5 million in investment banking fees from Apollo-related parties in connection with three separate transactions for three Apollo-related parties. Following this discussion, Piper Sandler confirmed that there were no material updates to its financial analysis with respect to the Merger Consideration delivered at the Board’s April 24 meeting. At the request of the Board, Piper Sandler then rendered its oral opinion to the Board, which was subsequently confirmed by delivery of its written opinion, dated April 26, 2024, which is attached to this proxy statement as Annex B, that, as of such date, and based upon and subject to the various assumptions made, procedures followed, matters considered and qualifications and limitations on the scope of review undertaken by Piper Sandler as set forth in its written opinion, the Merger Consideration was fair, from a financial point of view, to the holders of Shares (other than Excluded Shares), as set forth in such opinion as more fully described in the section of this proxy statement entitled “The Merger—Opinion of Piper Sandler.” Following this discussion, members of U.S. Silica’s management discussed with the Board the proposed communications strategy in connection with the announcement of the proposed transaction, and representatives of Piper Sandler led a discussion of the process that would begin once the 45 day go-shop period commenced after the announcement of the transaction, including with respect to planned outreach to potential bidders, including Party B.

Following further discussion and deliberation, including taking into account the factors described below in greater detail in the section of this proxy statement entitled “—Recommendation of Our Board of Directors and Reasons for the Merger,” the Board, among other things, unanimously (i) determined that the Merger Agreement and the transactions contemplated thereby, including the Merger, were fair, advisable and in the best interests of U.S. Silica and U.S. Silica Stockholders, (ii) approved, adopted and declared advisable the Merger Agreement and the transactions contemplated thereby, including the Merger, and (iii) resolved to submit and, subject to the terms and conditions of the Merger Agreement, recommend the Merger Agreement to U.S. Silica Stockholders for approval and adoption.

Following the meeting of the Board on April 26, 2024, representatives of the parties executed the transaction documents. Before the opening of the market on April 26, 2024, U.S. Silica issued a press release announcing the transaction, followed by U.S. Silica’s earnings press release for the first quarter of 2024. The press release announcing the transaction also noted that the Merger Agreement included a 45 day go-shop period that would expire at 12:01 a.m. (Eastern time) on June 10, 2024.

On April 26, 2024, immediately after the announcement, representatives of Piper Sandler, acting at the direction of the Board, began contacting potential counterparties that might consider making an alternative acquisition proposal in connection with the go-shop period, including Party B.

In connection with the go-shop period, representatives of Piper Sandler communicated with 95 parties to gauge such parties’ interest in making an alternative acquisition proposal. Of those 95 parties, U.S. Silica executed a confidentiality agreement with    parties. None of the confidentiality agreements contained a standstill provision.

Recommendation of Our Board of Directors and Reasons for the Merger

Recommendation of Our Board of Directors

The Board, after consulting with its financial advisor and outside legal counsel and reviewing and considering various factors described in “—Reasons for the Merger,” unanimously (i) determined that the transactions contemplated by the Merger Agreement, including the Merger, are advisable, fair to and in the best interests of U.S. Silica and the U.S. Silica Stockholders, (ii) approved, adopted and declared advisable the Merger Agreement and the transactions contemplated thereby, including the Merger, (iii) directed that the Merger Agreement be submitted to the U.S. Silica Stockholders for approval and adoption and (iv) recommended that the U.S. Silica Stockholders approve and adopt the Merger Agreement.

49

The Board unanimously recommends that you vote (i) “FOR” the Merger Proposal, (ii) “FOR” the Merger Compensation Proposal and (iii) “FOR” the Adjournment Proposal.

Reasons for the Merger

In evaluating the transactions contemplated by the Merger Agreement and reaching its decision that the Merger Agreement and the transactions contemplated thereby, including the Merger, are advisable, fair to and in the best interests of U.S. Silica and the U.S. Silica Stockholders, to approve, adopt and declare advisable the Merger Agreement and the transactions contemplated thereby, including the Merger, to direct that the Merger Agreement be submitted to the U.S. Silica Stockholders for approval and adoption, and to recommend that the U.S. Silica Stockholders approve and adopt the Merger Agreement, the Board of Directors consulted with U.S. Silica’s senior management, as well as U.S. Silica’s financial advisor and outside legal counsel, and considered a number of factors, including the following material factors that the Board of Directors viewed as supporting its decision (not necessarily in order of relative importance):

50

51

52

The Board of Directors also considered a variety of risk and other potential negative factors in its consideration of the Merger Agreement and the Merger, including the following material potentially negative factors (not necessarily in order of relative importance):

53

The foregoing discussion summarizes the material factors considered by the Board of Directors, but is not intended to be exhaustive. In light of the variety of factors considered in connection with its evaluation of the Merger, the Board of Directors did not find it practicable to, and did not, quantify, rank or otherwise assign relative weights to the specific factors considered in reaching its determination and recommendation. Moreover, each member of the Board of Directors applied his or her own business judgment to the process and may have given different weight to different factors. The Board of Directors did not undertake to make any specific determination as to whether any factor, or any particular aspect of any factor, supported or did not support its ultimate determination and recommendation. The Board of Directors based its recommendation on the totality of the information presented, including its discussions with, and questioning of, U.S. Silica’s executive management and its financial advisor and outside legal counsel. The above factors are not presented in any order of priority. This explanation of the reasoning of the Board of Directors and certain information presented in this section is forward-looking in nature and should be read in light of the factors set forth in “Cautionary Statement Regarding Forward-Looking Statements” on page 24 of this proxy statement.

Opinion of Piper Sandler

The Company engaged Piper Sandler to act as its financial advisor with respect to a potential transaction, including a possible sale of the Company. On April 26, 2024, Piper Sandler rendered its oral opinion (which

54

opinion was subsequently confirmed in writing) to the Board that, as of such date and based upon and subject to the various assumptions made, procedures followed, matters considered and qualifications and limitations on the scope of review undertaken by Piper Sandler as set forth in its written opinion, the Merger Consideration was fair, from a financial point of view, to the holders of Shares (other than Excluded Shares).

The full text of Piper Sandler’s written opinion, dated April 26, 2024, which sets forth, among other things, the assumptions made, procedures followed, matters considered and limitations on the scope of the review undertaken by Piper Sandler in rendering its opinion, is attached as Annex B to this proxy statement and is incorporated by reference herein. Piper Sandler’s opinion addressed solely the fairness, from a financial point of view, to the holders of Shares, of the Merger Consideration and does not address any other terms or agreements relating to the Merger or any other terms of the Merger Agreement. Piper Sandler’s opinion was provided to the Board in connection with its consideration of the Merger and was not intended to be, and does not constitute, a recommendation to any U.S. Silica Stockholder as to how such U.S. Silica Stockholder should act or vote with respect to the Merger or any other matter. U.S. Silica Stockholder are urged to read the opinion in its entirety. Piper Sandler’s opinion was approved for issuance by the Piper Sandler opinion committee.

In connection with rendering the opinion described above and performing its related financial analyses, Piper Sandler, among other things:

In addition, Piper Sandler conducted such other analyses, examinations and inquiries and considered such other financial, economic and market criteria as Piper Sandler deemed necessary in arriving at its opinion.

The following is a summary of the material financial analyses performed by Piper Sandler in connection with the preparation of its fairness opinion and reviewed with the Board at a meeting thereof held on April 26, 2024.

This summary includes information presented in tabular format, which tables must be read together with the text of each analysis summary and considered as a whole in order to fully understand the financial analyses presented by Piper Sandler. The tables alone do not constitute a complete summary of the financial analyses conducted by Piper Sandler. The order in which these analyses are presented below, and the results of those analyses, should not be taken as any indication of the relative importance or weight given to any of these analyses by Piper Sandler or the Board. Except as otherwise noted, the following quantitative information, to the extent that it is based on market data, is based on market data as it existed on or before April 25, 2024, and is not necessarily indicative of current market conditions.

55

Unless the context indicates otherwise, for purposes of the financial analyses described below, Piper Sandler calculated enterprise values (“EV”) defined as the relevant company’s fully-diluted common equity value (determined using the treasury stock method), plus, where applicable, book value of preferred stock, plus fair value of contingent consideration, plus debt, plus capital and operating leases, less cash and cash equivalents, less investments in partnerships, and less short- and long-term investments (“net debt”), plus, where applicable, book value of non-controlling interests. In the case of each publicly traded company included in the selected public companies analysis described below under the heading “Selected Public Companies Analysis”, EV was based on (i) the market value of the relevant company’s common equity, using closing stock prices on April 25, 2024, and (ii) the relevant company’s net debt as of such company’s most recently reported quarter end, and in the case of each target company included in the selected merger and acquisition (“M&A”) transactions analysis described below under the heading “Selected M&A Transactions Analysis,” EV was based on (i) the implied value of the relevant target company’s common equity using the implied purchase price paid for such target company’s common equity in the relevant M&A transaction and the relevant target company’s net debt as of such target company’s most recently reported quarter end immediately prior to announcement of the relevant M&A transaction (in the case of M&A transactions involving the acquisition of public companies) or otherwise (ii) the publicly announced EV for the target company at the time of announcement of the relevant M&A transaction.

Additionally, references to (a) “EBITDA” are references to earnings before interest, tax, depreciation and amortization, adjusted for stock-based compensation, (b) “LTM” historical financial information are references to (i) for each target company included in the selected M&A transactions described below under the heading “Selected M&A Transactions Analysis,” the last 12-month period for which financial information was publicly available as of immediately prior to the announcement of the relevant M&A transaction, based on such publicly available information, and (ii) for the Company, based on historical financial information provided by U.S. Silica’s management to Piper Sandler, and (c) projected financial information (i) for each target company included in the selected M&A transactions analysis described below are based on Wall Street consensus equity research estimates (“Consensus Estimates”) or disclosure by such target company and (ii) for the Company, based on the Financial Projections.

Summary of Piper Sandler’s Financial Analysis

As part of its “Selected Public Companies Analysis” and “Selected M&A Transactions Analysis,” Piper Sandler considered the Company as two independent businesses: the industrial and specialty products segment and the oil and gas proppants segment. After analyzing the industrial and specialty products segment and the oil and gas proppants segment, Piper Sandler combined the high valuations of each segment and the low valuations of each segment as implied by their respective valuation methodologies as summarized below to arrive at high and low valuation ranges of the Company on a sum-of-the-parts basis. When performing such analysis, Piper Sandler considered a “No Burdens” case for each business segment, which applied reference range multiples to each business segment and did not include any additional standalone cost structure or other deductions, and an “Adjustment Burdening” case, which applied reference range multiples to each business segment and (i) applied to each business segment $5 million in dis-synergies to operate independently for the selected public companies analysis described below under the heading “Selected Public Companies Analysis” and the selected M&A transactions analysis described below under the heading “Selected M&A Transactions Analysis” and (ii) assumed a 20% capital gains tax applied to net asset value greater than $478 million for the oil and gas proppants segment, which Piper Sandler assumed was such segment’s tax basis based on information provided by U.S. Silica’s management, in connection with the selected M&A transactions analysis described below under the heading “Selected M&A Transactions Analysis.”

Selected Public Companies Analysis

Industrial and Specialty Products Segment

Piper Sandler reviewed, among other things, projected financial data prepared by the Company management for calendar year 2024 as included in the Financial Projections and compared such data to corresponding

56

Consensus Estimates for calendar year 2024 for certain selected comparable publicly traded industrial minerals companies. The criteria used for selecting the comparable companies was that each selected company (i) be a publicly traded industrial minerals company, (ii) have a market capitalization between $500 million and $2.5 billion, (iii) derive a meaningful portion of revenue from mineral products and (iv) operate primarily in North America and Europe.

Based on these criteria, Piper Sandler selected the following public companies and calculated the EV and EBITDA for calendar year 2024 (“2024 EBITDA”) for each selected public company, and then derived the EV/2024 EBITDA multiples for the selected public companies. This analysis indicated, to the extent sufficient information was publicly available, the following EV/2024 EBITDA multiples:

Piper Sandler then derived high and low EVs for the industrial and specialty products segment by applying a 8.3x multiple to the high-end of the range and a 7.3x multiple to the low-end of the range. Piper Sandler selected this range based on its professional judgment and experience.

For the Adjustment Burdening case, this derivation resulted in implied high and low EVs of approximately $1,112 million and $978 million, respectively. For the No Burdens case, this derivation resulted in implied high and low EVs of approximately $1,154 million and $1,015 million, respectively.

Oil and Gas Proppants Segment

Piper Sandler reviewed, among other things, projected financial data prepared by the Company management for calendar year 2024 as included in the Financial Projections and compared such data to corresponding Consensus Estimates for calendar year 2024 for comparable publicly traded frac services, proppant and related logistics companies. The criteria used for selecting the comparable companies was that each selected company (i) be a publicly traded frac services, proppant and related logistics company, (ii) have a market capitalization between $100 million and $5 billion, (iii) derive a meaningful portion of revenue from hydraulic fracturing related services and (iv) operate primarily in onshore North America.

Based on these criteria, Piper Sandler selected the following public companies and calculated the EV and the 2024 EBITDA for each selected public company, and then derived the EV/2024 EBITDA multiples for the selected public companies. This analysis indicated the following EV/2024 EBITDA multiples:

57

Piper Sandler then derived high and low EVs for the oil and gas proppants segment by applying a 3.5x multiple to the high-end of the range and a 3.0x to the low-end of the range. Based on its professional judgment and experience, Piper Sandler selected this range because the two closest comparable companies are significantly larger than the oil and gas proppants segment and, based on the Financial Projections, the EBITDA of the oil and gas proppants segment has a negative growth profile.

For the Adjustment Burdening case, this derivation resulted in implied high and low EVs of approximately $734 million and $629 million, respectively. For the No Burdens case, this derivation resulted in implied high and low EVs of approximately $752 million and $644 million, respectively.

Sum-of-the-Parts

After analyzing the industrial and specialty products segment and the oil and gas proppants segment, Piper Sandler then combined the high valuations of each segment and low valuations of each segment as implied by the analysis described above to arrive at per share (rounded to the nearest $0.05) valuation ranges of the Company on a whole company basis. Piper Sandler observed that the Merger Consideration was within each of the ranges derived from the analyses.

The high and low per share values for the Adjustment Burdening case and the No Burden case were calculated by (i) (x) adding (1) the implied high and low EVs for the industrial and specialty products segment for such case as set forth in “Selected Public Companies Analysis—Industrial and Specialty Products Segment” and (2) the implied high and low EVs for the oil and gas proppants segment for such case as set forth in “Selected Public Companies Analysis—Oil and Gas Proppants Segment,” respectively, subtracting (y) the Company’s net debt and noncontrolling interests from each amount, and (ii) dividing the resulting amounts by the Company’s fully diluted shares of the Common Stock outstanding as of March 31, 2024.

Selected M&A Transaction Analysis

Industrial and Specialty Products Segment

Piper Sandler reviewed selected M&A transactions announced since January 1, 2014, involving industrial minerals businesses in North America and Europe, in which the acquiring company purchased a controlling interest of the target.

58

Based on these criteria, Piper Sandler identified and analyzed the following 10 selected transactions. For this selected M&A transactions analysis, Piper Sandler calculated the EV and LTM EBITDA for each selected M&A transaction, and then derived the EV/LTM EBITDA multiples for the selected M&A transactions. The analysis indicated the following EV/LTM EBITDA multiples for the selected M&A transactions:

Piper Sandler then derived the implied high and low EVs for the industrial and specialty products segment by applying a 9.7x multiple to the high-end of the range and a 8.7x multiple to the low-end of the range. Piper Sandler selected this range based on its professional judgment and experience.

For the Adjustment Burdening case, this derivation resulted in implied high and low EVs of approximately $1,266 million and $1,136 million, respectively. For the No Burdens case, the analysis resulted in implied high and low EVs of approximately $1,315 million and $1,179 million, respectively.

Oil and Gas Proppants Segment

Piper Sandler reviewed selected M&A transactions announced since January 1, 2021, involving oil and gas proppant and proppant logistics businesses in North America, in which the acquiring company purchased a controlling interest of the target.

59

Based on these criteria, Piper Sandler identified and analyzed the below 5 selected transactions. For this selected M&A transactions analysis, Piper Sandler calculated the EV and, to the extent sufficient information was publicly available, the next twelve-month EBITDA (“NTM EBITDA”) for each selected M&A transaction, and then derived the EV/NTM EBITDA for the selected M&A transactions. The analysis indicated the following EV/NTM EBITDA multiples for the selected M&A transactions:

Piper Sandler then derived the implied high and low EVs for the oil and gas proppants segment by applying a 3.5x multiple to the high-end of the range and a 3.0x multiple to the low-end of the range. Piper Sandler selected this range based on its professional judgment and experience.

For the Adjustment Burdening case, this derivation resulted in implied high and low EVs of approximately $734 million and $629 million, respectively. For the No Burdens case, this derivation resulted in implied high and low EVs of approximately $752 million and $644 million, respectively.

Sum-of-the-Parts

After analyzing the industrial and specialty products segment and oil and gas proppants segment, Piper Sandler then combined the high and low valuations of each segment as implied by the analysis described above to arrive at per share (rounded to the nearest $0.05) valuation ranges of the Company on a whole company basis. Piper Sandler observed that the Merger Consideration was within each of the ranges derived from the analyses.

The high and low per share values for the Adjustment Burdening case and the No Burden case were calculated by (i) (x) adding (1) the implied high and low EVs for the industrial and specialty products segment for such case as set forth in “Selected M&A Transaction Analysis—Industrial and Specialty Products Segment” and (2) the implied high and low EVs for the oil and gas proppants segment for such case as set forth in “Selected M&A Transaction Analysis—Oil and Gas Proppants Segment,” respectively, subtracting (y)(1) solely for the Adjustment Burdening case, an amount equal to 20% capital gains tax leakage to the extent the EV amounts for the oil and gas proppants segment exceed $478 million and (2) the Company’s net debt and noncontrolling interests from each amount, and (ii) dividing the resulting amounts by the Company’s fully diluted shares of the Common Stock outstanding as of March 31, 2024.

60

Discounted Cash Flow Analysis

Using a discounted cash flows analysis, Piper Sandler calculated an estimated range of theoretical EVs for the Company based on the present value of (i) projected unlevered after-tax free cash flows to the Company for June 30, 2024 through calendar year 2028 and (ii) a projected terminal value at December 31, 2028 based upon perpetuity growth rates between -0.5% and 0.5% for the oil and gas proppants segment and perpetuity growth rates between 2.5% and 3.5% for the industrial and specialty products segment, selected by Piper Sandler based on its professional judgment, and in each case, discounted back to June 30, 2024. The after-tax free cash flows to the Company for each calendar year and terminal year value were calculated from the Financial Projections. Piper Sandler calculated the range of present values for free cash flows to the Company for such periods based on a range of discount rates ranging from 13.3% to 14.3%, based on its estimation of the Company’s weighted average cost of capital of 13.8%. This analysis resulted in implied per share values for the Common Stock ranging from $13.00 to $15.70 per share, rounded to the nearest $0.05. Piper Sandler observed that the Merger Consideration was within the implied per share value derived from this analysis.

Miscellaneous

The summary set forth above does not contain a complete description of the analyses performed by Piper Sandler and reviewed with the Board. The preparation of a fairness opinion is not necessarily susceptible to partial analysis or summary description. Piper Sandler believes that its analyses and the summary set forth above must be considered as a whole and that selecting portions of its analyses or of the summary, without considering the analyses as a whole or all of the factors included in its analyses, would create an incomplete view of the processes underlying the analyses set forth in Piper Sandler’s opinion. In arriving at its opinion, Piper Sandler considered the results of all of its analyses and did not attribute any particular weight to any factor or analysis. Instead, Piper Sandler made its determination as to fairness on the basis of its experience and financial judgment after considering the results of all of its analyses. In addition, the ranges of valuations resulting from any particular analysis described above should not be taken to be Piper Sandler’s view of the actual value of the Company.

None of the selected companies or transactions used in the analyses above is directly comparable to the Company or the Merger. Accordingly, an analysis of the results of the comparisons is not purely mathematical; rather, it involves considerations and judgments concerning differences in historical and projected financial and operating characteristics of the selected companies and target businesses in the selected transactions and other factors that could affect the public trading values of such companies or transaction values of such businesses.

Piper Sandler performed its analyses for purposes of providing its opinion to the Board. In performing its analyses, Piper Sandler made numerous assumptions with respect to industry performance, general business and economic conditions and other matters. Certain of the analyses performed by Piper Sandler were based upon the Financial Projections furnished to Piper Sandler by U.S. Silica’s management, which are not necessarily indicative of actual future results and may be significantly more or less favorable than actual future results. The Financial Projections are inherently subject to uncertainty because, among other things, they are based upon numerous factors or events beyond the control of the parties or their respective advisors and representatives. Piper Sandler does not assume responsibility if future results are materially different from projected financial results.

Piper Sandler’s opinion was one of many factors taken into consideration by the Board in making the determination to approve the Merger Agreement. While Piper Sandler provided advice to the Board during the Company’s negotiations with Apollo, Piper Sandler did not recommend any specific amount or type of consideration to the Board or that any specific amount or type of consideration constituted the only appropriate consideration for the Merger.

Piper Sandler relied upon and assumed, without assuming liability or responsibility for independent verification, the accuracy and completeness of all information that was publicly available or was furnished, or

61

otherwise made available, to Piper Sandler or discussed with or reviewed by Piper Sandler. Piper Sandler further relied upon the assurances of U.S. Silica’s management that the financial information provided has been prepared on a reasonable basis in accordance with industry practice, and that they are not aware of any information or facts that would make any information provided to Piper Sandler incomplete or misleading. Without limiting the generality of the foregoing, for the purpose of its opinion, Piper Sandler assumed that with respect to financial forecasts, estimates and other forward-looking information reviewed by Piper Sandler, that such information was reasonably prepared based on assumptions reflecting the best currently available estimates and judgments of U.S. Silica’s management as to the expected future results of operations and financial condition of the Company. Piper Sandler expressed no opinion as to any such financial forecasts, estimates or forward-looking information or the assumptions on which they were based. Piper Sandler relied, with the consent of the Board, on advice of the outside counsel and the independent accountants to the Company, and on the assumptions of U.S. Silica’s management, as to all accounting, legal, tax and financial reporting matters with respect to the Company and the Merger Agreement.

In arriving at its opinion, Piper Sandler relied upon and assumed, without independent verification, that (i) the representations and warranties of all parties to the Merger Agreement and all other related documents and instruments that are referred to therein were true and correct, (ii) each party to such agreements will fully and timely perform all of the covenants and agreements required to be performed by such party, (iii) the Merger will be consummated pursuant to the terms of the Merger Agreement without amendments thereto and (iv) all conditions to the consummation of the Merger will be satisfied without waiver by any party of any conditions or obligations thereunder. Additionally, Piper Sandler assumed that all the necessary regulatory approvals and consents required for the Merger will be obtained in a manner that will not adversely affect the Company or the contemplated benefits of the Merger.

In arriving at its opinion, Piper Sandler did not perform any appraisals or valuations of any specific assets or liabilities (fixed, contingent or other) of the Company, and was not furnished or provided with any such appraisals or valuations, nor did Piper Sandler evaluate the solvency of the Company under any state or federal law relating to bankruptcy, insolvency or similar matters. The analyses performed by Piper Sandler in connection with its opinion were going concern analyses. Piper Sandler expressed no opinion regarding the liquidation value of the Company or any other entity. Without limiting the generality of the foregoing, Piper Sandler undertook no independent analysis of any pending or threatened litigation, regulatory action, possible unasserted claims or other contingent liabilities, to which the Company or any of its affiliates is a party or may be subject and, at the direction of the Board and with its consent, Piper Sandler’s opinion made no assumption concerning, and therefore did not consider, the possible assertion of claims, outcomes or damages arising out of any such matters. Piper Sandler also assumed that neither the Company nor Parent is party to any material pending transaction, including without limitation any financing, recapitalization, acquisition or merger, divestiture or spin-off, other than the Merger.

Piper Sandler’s opinion was necessarily based upon the information available to it and facts and circumstances as they existed and were subject to evaluation on the date of its opinion. Events occurring after the date of Piper Sandler’s opinion could materially affect the assumptions used in preparing its opinion. Piper Sandler expressed no opinion as to the price at which the Shares may trade following announcement of the Merger or at any future time. Piper Sandler did not undertake to reaffirm or revise its opinion or otherwise comment upon any events occurring after the date of its opinion and does not have any obligation to update, revise or reaffirm its opinion.

Piper Sandler’s opinion addressed solely the fairness, from a financial point of view, to the holders of Shares of the Merger Consideration set forth in the Merger Agreement and did not address any other terms or agreement relating to the Merger or any other terms of the Merger Agreement. Piper Sandler was not requested to opine as to, and its opinion does not address, the basic business decision to proceed with or effect the Merger, the merits of the Merger relative to any alternative transaction or business strategy that may be available to the Company, Parent’s ability to fund the aggregate merger consideration, or any other terms contemplated by the

62

Merger Agreement or the fairness of the Merger to any other class of securities, creditor or other constituency of the Company. Furthermore, Piper Sandler expressed no opinion with respect to the amount or nature of compensation to any officer, director, or employee of any party to the Merger, or any class of such persons, relative to the compensation to be received by the Shares in the Merger or with respect to the fairness of any such compensation.

Information about Piper Sandler

As a part of its investment banking business, Piper Sandler is regularly engaged in the valuation of businesses in oil and gas proppants, industrial minerals and other industries and their securities in connection with mergers and acquisitions, underwritings, secondary distributions of listed and unlisted securities, private placements, and valuations for corporate and other purposes. The Board selected Piper Sandler to be its financial advisor and render its fairness opinion in connection with the Merger on the basis of such experience and its familiarity with the Company.

Piper Sandler acted as financial advisor to the Company in connection with the Merger and will receive a fee from the Company for providing its services equal to $15,000,000, the entirety of which is contingent upon the consummation of the merger. Piper Sandler also received a fee of $2,000,000 for rendering its fairness opinion. The opinion fee was not contingent upon the consummation of the Merger or the conclusions reached in Piper Sandler’s opinion. The Company has also agreed to indemnify Piper Sandler against certain liabilities and to reimburse Piper Sandler for certain expenses in connection with its services. In addition, as of April 26, 2024, Piper Sandler and its affiliates did not hold any ownership position in the Company or Apollo; however, in the ordinary course of its business, Piper Sandler and its affiliates may actively trade securities of the Company or Apollo, for their own accounts or the accounts of their customers and, accordingly, may at any time hold a long or short position in such securities. Piper Sandler may also, in the future, provide investment banking and financial advisory services to the Company, Apollo or entities that are affiliated with the Company or Apollo, for which Piper Sandler would expect to receive compensation.

Consistent with applicable legal and regulatory requirements, Piper Sandler has adopted policies and procedures to establish and maintain the independence of Piper Sandler’s research department and personnel. As a result, Piper Sandler’s research analysts may hold opinions, make statements or recommendations and/or publish research reports with respect to the Company and the Merger and other participants in the Merger that differ from the views of Piper Sandler’s investment banking personnel.

Since January 1, 2021, Piper Sandler and its investment banking affiliates have not received any revenue in respect of any financial advisory or other investment banking services provided to the Company and its affiliates. Piper Sandler or its investment banking affiliates maintain an ongoing dialogue with Apollo and certain of its affiliates and portfolio companies, in an effort to obtain investment banking work and related compensation. Since January 1, 2021, Piper Sandler and its investment banking affiliates have received approximately $3.5 million in investment banking fees from Apollo-related parties in connection with three separate transactions for three Apollo-related parties. As of April 26, 2024, neither Piper Sandler nor any of its investment banking affiliates were engaged as a financial advisor to any portfolio company of Apollo, but after April 26, 2024, Piper Sandler or one of its investment banking affiliates has been engaged as a financial advisor to a portfolio company of Apollo, for which Piper Sandler would expect to receive fees up to $3,000,000, should a transaction be completed.

Certain Unaudited Financial Projections

Other than providing certain limited periodic earnings guidance, U.S. Silica does not, as a matter of course, make public projections as to future performance, revenues, production, earnings or other results reflecting an extended period due to, among other reasons, the inherent difficulty of accurately predicting financial performance for future periods and the uncertainty, unpredictability and subjectivity of underlying assumptions

63

and estimates. In the ordinary course of business, however, U.S. Silica management prepares a long-term strategic plan that reflects U.S. Silica management’s financial and business outlook for U.S. Silica, which is updated on a periodic basis and reviewed with the Board. In February 2024, in connection with the repricing of U.S. Silica’s seven-year $950 million senior secured Term Loan B due March 23, 2030, which repricing occurred in March 2024, U.S. Silica’s management prepared certain non-public, unaudited, five-year financial projections, on a standalone basis, for U.S. Silica (the “Financial Projections”). In April 2024, the Board approved the Financial Projections for use by Piper Sandler in connection with performing its financial analyses summarized under “—Opinion of Piper Sandler” beginning on page 54 of this proxy statement. U.S. Silica is including in this proxy statement a summary of the Financial Projections, solely because the Financial Projections were reviewed by the Board in connection with its consideration and evaluation of the Merger, and provided to Piper Sandler for its use in connection with the financial analysis presented by Piper Sandler to the Board as discussed in the section of this proxy statement entitled “—Opinion of Piper Sandler,” and provided to Parent and Merger Sub.

The Financial Projections were prepared treating U.S. Silica on a standalone basis, without giving effect to the Merger, including any impact of the negotiation or execution of the Merger, the expenses that may be incurred in connection with the Merger or the consummation thereof, the effect of any business or strategic decision or action that has been or will be taken as a result of the Merger Agreement having been executed or in anticipation of the Merger, or the effect of any alteration, acceleration, postponement or decision not to take any business or strategic decisions or actions that would likely have been taken if the Merger Agreement had not been executed but which were instead altered, accelerated, postponed or not taken in anticipation of the Merger. Further, the Financial Projections do not take into account the effect on U.S. Silica of any possible failure of the proposed Merger to occur.

Although a summary of the Financial Projections is presented with numerical specificity, U.S. Silica’s ability to achieve the results set forth in the Financial Projections is expressly dependent upon certain assumptions, are subjective in many respects and subject to multiple interpretations and frequent revisions attributable to the dynamics of U.S. Silica’s industry and based on actual experience and business developments, industry performance, general business, economic, regulatory, market and financial conditions, and other matters, many of which are difficult to predict, subject to significant economic and competitive uncertainties, and beyond U.S. Silica’s control including, among others, future results, oil and gas industry activity, industrial minerals industry activity, commodity prices, demand for oil and natural gas, the availability of sufficient cash flow or financing to fund the exploration and development costs associated with projected drilling programs, accuracy of certain industry forecasts prepared by third parties, the effectiveness of U.S. Silica’s research and development and new product introductions, general economic and regulatory conditions and other matters described in the sections of this proxy statement entitled “Cautionary Statement Concerning Forward-Looking Statements,” “Where You Can Find More Information” and “Risk Factors.” The Financial Projections also reflect assumptions as to certain business decisions that are subject to change and are susceptible to multiple interpretations and periodic revisions based on actual results, revised prospects for U.S. Silica’s business, competitive environment, changes in general business or economic conditions, or any other transaction or event that has occurred or that may occur and that was not anticipated when the Financial Projections were prepared, or any other changes that may in the future affect U.S. Silica’s assets, business, operations, properties, policies, corporate structure, capitalization and management as a result of the proposed transaction or otherwise.

As a result, there can be no assurance that the Financial Projections will be realized, and actual results may be materially better or worse than those contained in the Financial Projections. The Financial Projections cannot be considered a guarantee of future operating results and should not be relied upon as such. Since the Financial Projections cover multiple years, such information by its nature becomes less reliable with each successive year. The Financial Projections do not take into account any circumstances or events occurring after the date on which they were prepared, including the Merger, and some or all of the assumptions that have been made in connection with the preparation of the Financial Projections may have changed since the date the Financial Projections were prepared. Economic and business environments can and do change quickly, which adds an additional significant

64

level of uncertainty as to whether the results portrayed in the Financial Projections will be achieved. In addition, the Financial Projections have not been updated or revised to reflect information or results after the date the Financial Projections were prepared.

The Financial Projections should be evaluated, if at all, in conjunction with the historical financial statements, risk factors and other information regarding U.S. Silica contained in U.S. Silica’s public filings with the SEC. See “Where You Can Find More Information” on page 126 of this proxy statement. Except to the extent required by applicable federal securities laws, U.S. Silica does not intend, and expressly disclaims any responsibility, to update or otherwise revise the Financial Projections to reflect circumstances existing after the date when U.S. Silica prepared the Financial Projections or to reflect the occurrence of future events or changes in general economic or industry conditions, even if the assumptions underlying the Financial Projections are shown to be in error. These considerations should be taken into account in reviewing the Financial Projections, which were prepared as of an earlier date.

The inclusion of this information should not be regarded as an indication that the Board, U.S. Silica, U.S. Silica’s financial advisors, representatives and affiliates, Parent, Parent’s representatives and affiliates (including Apollo) or any other recipient of this information considered, or now considers, the Financial Projections an accurate or reliable prediction of future results, to be material information of U.S. Silica or that actual future results will necessarily reflect the Financial Projections, and the Financial Projections should not be relied upon as such. The summary of the Financial Projections is not included herein to induce any stockholder to vote in favor of the Merger Proposal or any of the other proposals to be voted on at the Special Meeting or to influence any stockholder to make any investment decision with respect to the Merger, including whether or not to seek appraisal rights with respect to shares of Common Stock.

In light of the foregoing factors and the uncertainties inherent in any forecasting assumptions and information, readers of this proxy statement are cautioned not to place undue reliance on the Financial Projections included herein.

The Financial Projections were not prepared with a view to public disclosure and are included herein only because such information was made available as described above. The Financial Projections were not prepared with a view to complying with accounting principles generally accepted in the United States (“GAAP”), the published guidelines of the SEC or the guidelines established by the American Institute of Certified Public Accountants for preparation and presentation of prospective financial information. Furthermore, the Financial Projections included in this document have been prepared by, and are the responsibility of, U.S. Silica’s management. Grant Thornton LLP has not audited, reviewed, examined, compiled nor applied agreed-upon procedures with respect to the accompanying prospective Financial Projections and, accordingly, Grant Thornton LLP does not express an opinion or any other form of assurance with respect thereto. The Grant Thornton LLP report incorporated by reference in this document relates to U.S. Silica’s previously issued financial statements. It does not extend to the Financial Projections and should not be read to do so.

The Financial Projections contain certain non-GAAP financial measures that U.S. Silica believes are helpful in understanding its past financial performance and future results. U.S. Silica’s management regularly uses a variety of financial measures that are not in accordance with GAAP for forecasting, budgeting and measuring financial performance. Non-GAAP financial measures should not be considered in isolation from, or as a substitute for, financial information presented in accordance with GAAP. While U.S. Silica believes that these non-GAAP financial measures provide meaningful information to help investors understand the operating results and to analyze U.S. Silica’s financial and business trends on a period-to-period basis, there are limitations associated with the use of these non-GAAP financial measures. These non-GAAP financial measures are not prepared in accordance with GAAP, are not reported by all of U.S. Silica’s competitors and may not be directly comparable to similarly titled measures of U.S. Silica’s competitors due to potential differences in the exact method of calculation. The SEC rules that would otherwise require a reconciliation of an adjusted financial measure to a GAAP financial measure do not apply to adjusted financial measures provided to a board of

65

directors or a financial advisor in connection with a proposed business combination such as the Merger if the disclosure is included in a document such as this proxy statement. In addition, reconciliations of adjusted financial measures were not relied upon by the Board or U.S. Silica’s management or financial advisors in connection with their respective evaluation of the Merger. Accordingly, U.S. Silica has not provided a reconciliation of the non-GAAP financial measures included in the Financial Projections to the relevant GAAP financial measures.

U.S. Silica’s management prepared the Financial Projections, as a standalone company, for fiscal year 2024 through fiscal year 2028. The following table summarizes the Contribution Margin, Adjusted EBITDA, and Unlevered Free Cash Flow reflected in the Financial Projections, with dollars in millions.

U.S. Silica has not made and makes no representation to any U.S. Silica Stockholder or to Apollo, Parent, Merger Sub or the Equity Investors in the Merger Agreement or otherwise concerning the Financial Projections or regarding U.S. Silica’s ultimate performance compared to the information contained in the Financial Projections or that the projected results will be achieved.

Interests of the Directors and Officers of U.S. Silica in the Merger

When considering the recommendation of the Board that you vote “FOR” the Merger Proposal, you should be aware that certain of our directors and executive officers may have interests in the Merger that may be different from, or in addition to, your interests as a stockholder generally. To the extent such interests existed at the time, the Board was aware of these interests in, among other matters, approving the Merger Agreement and the Merger and in recommending that the Merger Agreement be approved and adopted by the U.S. Silica Stockholders. See “— Background of the Merger” and “— Recommendation of Our Board of Directors and Reasons for the Merger” on pages 37 and 49 of this proxy statement, respectively. You should take these interests into account in deciding whether to vote “FOR” the approval of the Merger Proposal.

These interests are described in more detail below, and certain of them, including the compensation that may become payable in connection with the Merger to Messrs. Shinn, Hough, Ussery, Carusona and Merril, and

66

Ms. Russell, who constitute our named executive officers, are subject to a non-binding, advisory vote of the U.S. Silica Stockholders and are quantified in the narrative below and in “Advisory Vote on Merger-Related Named Executive Officer Compensation (The Merger Compensation Proposal)” on page 119 of this proxy statement. The dates used below to quantify these interests have been selected for illustrative purposes only and do not necessarily reflect the dates on which certain events will occur.

Treatment of Equity and Equity-Based Awards

Under the Merger Agreement, the equity-based awards held by U.S. Silica’s directors and executive officers granted under the U.S. Silica Holdings, Inc. 2011 Incentive Compensation Plan, as amended and restated from time to time (the “Company Equity Plan”) will be treated as follows:

Company RSUs

Each Company RSU that is outstanding immediately prior to the Effective Time, will vest in full and be cancelled in exchange for the right to receive an amount in cash (subject to any applicable withholding taxes) equal to the product of (x) the number of Shares subject to the Company RSU immediately prior to the Effective Time, multiplied by (y) the Merger Consideration.

Company PSUs

Each Company PSU that is outstanding immediately prior to the Effective Time will vest in full and be cancelled in exchange for the right to receive an amount in cash (subject to any applicable withholding taxes) equal to the product of (x) the number of Shares subject to the Company PSU immediately prior to the Effective Time, multiplied by (y) the Merger Consideration. For purposes of determining the number of Shares subject to a Company PSU immediately prior to the Effective Time: (A) in the case of TSR Company PSUs, the number of Shares will be based on the greater of the target level and the actual level of performance measured as of the Measurement Date and using the value of the Merger Consideration as the “ending stock price” for calculating performance; and (B) in the case of ACF Company PSUs, the number of Shares will be based on (1) actual performance for performance periods completed prior to the Measurement Date, (2) the greater of the target level and the actual level of performance measured as of the Measurement Date for performance periods that are ongoing as of the Measurement Date and (3) target performance in respect of performance periods that have not commenced as of the Measurement Date.

Company Options

At the Effective Time, each Company Option that is outstanding and unexercised immediately prior to the Effective Time will be cancelled in exchange for the right to receive an amount in cash (subject to any applicable withholding taxes) equal to the product of (x) the excess, if any, of the Merger Consideration over the per Share exercise price of such Company Option, multiplied by (y) the number of Shares covered by such Company Option immediately prior to the Effective Time. If the per Share exercise price of such Company Option equals or exceeds the Merger Consideration, such Company Option shall be cancelled for no consideration.

The following table sets forth the number of outstanding Company RSUs and Company PSUs that were awarded to and held by our executive officers and directors as of May 23, 2024 under the Company Equity Plan and an estimate of the value of such awards (on a pre-tax basis) using a price per Share of $15.50 (i.e., the Merger Consideration). For TSR Company PSUs, the values set forth in the table below reflect the greater of target and actual performance as of May 23, 2024, calculated by using the value of the Merger Consideration as the “ending stock price”. For ACF Company PSUs with performance periods ending December 31, 2022 and 2023, the values set forth in the table below are based on actual performance, and for ACF Company PSUs with performance periods ending December 31, 2024, 2025 and 2026, the values set forth in the table below are based on target performance. All Company Options held by U.S. Silica’s executive officers as of May 23, 2024 are

67

fully vested and have an exercise price higher than the Merger Consideration, as a result of which, such Company Options will be cancelled for no consideration at the Effective Time. No U.S. Silica directors currently hold Company Options. Depending on the date upon which the closing of the Merger actually occurs, certain Company RSUs and Company PSUs that are unvested as of the date of this proxy statement and that are included in the table below may vest and settle pursuant to their terms, without regard to the Merger.

These amounts do not attempt to forecast any additional equity award grants, issuances or forfeitures that may occur prior to the closing of the Merger following the date of this proxy statement. As a result of the foregoing assumptions, which may or may not actually occur or be accurate on the relevant date, the actual amounts, if any, to be received by U.S. Silica executive officers and directors may materially differ from the amounts set forth above.

68

Director Equity Awards

After each annual meeting of stockholders, U.S. Silica grants the newly-appointed or elected outside members of the Board of Directors (including outside members of the Board of Directors re-elected at the annual meeting) a Company RSU award which vests one year following the grant date, subject to pro rata forfeiture if the director terminates service before the vesting date. Historically, the number of Company RSUs granted were determined by using the 30-trading day trailing average of U.S. Silica’s stock price on the date of grant. On May 9, 2024, U.S. Silica issued Company RSUs in the amounts set forth below to the members of the Board of Directors in the ordinary course of business, however, the number of Company RSUs granted was determined based on the Merger Consideration instead of the 30-trading day trailing average of U.S. Silica’s stock price on the date of grant. The amounts that were issued to the Chairman of the Board and Chairs of the committees of the Board were additional to the amount each such member was eligible to receive as a regular member of the Board.

Treatment of Common Stock

If the Merger Proposal is approved by U.S. Silica Stockholders, the Shares held by the directors and executive officers of U.S. Silica will be treated in the same manner as outstanding Shares held by all other U.S. Silica Stockholders entitled to receive the Merger Consideration.

As of May 23, 2024, directors and executive officers of U.S. Silica, as a group, held 2,341,412 outstanding Shares. At the Effective Time, each Share outstanding as of immediately prior to the Effective Time that is held by the directors and executive officers of U.S. Silica will be automatically converted into the right to receive the Merger Consideration.

Payments and Benefits Upon Termination at or Following a Change in Control

Employment Agreement with Mr. Shinn

In March 2012, U.S. Silica entered into an employment agreement with Mr. Shinn, U.S. Silica’s Chief Executive Officer, which has since been amended. Pursuant to the terms of Mr. Shinn’s employment agreement, as amended, in the event of Mr. Shinn’s termination without cause (and not as a result of Mr. Shinn’s death or disability) or if Mr. Shinn resigns for good reason, in either case occurring on or within 24 months after a change in control, which, for the avoidance of doubt, includes the Merger, Mr. Shinn is entitled to the following severance benefits: (a) a lump-sum payment equal to two times the sum of (i) Mr. Shinn’s annual base salary as of the termination date (or, if greater, the salary in effect on the first occurrence of the change in control) and (ii) Mr. Shinn’s target annual cash bonus for the year in which the termination occurs (or, if greater, the target annual cash bonus in effect on the first occurrence of the change in control), (b) a prorated annual bonus for the fiscal year in which the termination of employment occurs at the target level based on the number of days Mr. Shinn was employed during the year, and (c) continuation of group health insurance coverage for Mr. Shinn and Mr. Shinn’s eligible dependents pursuant to COBRA during the 18-month period following Mr. Shinn’s termination of employment.

Pursuant to the terms of the employment agreement, if Mr. Shinn’s employment is terminated without cause or Mr. Shinn resigns for good reason and such termination or resignation is not in connection with a change in control, Mr. Shinn is entitled to receive severance equal to his annual base salary payable in regular installments

69

from the date of termination through the twelve-month anniversary of the date of termination and reimbursement of the then-prevailing monthly premium for COBRA healthcare coverage, if he so elects, for 12 months after such termination.

Receipt of the foregoing severance benefits is conditioned upon Mr. Shinn executing a general release of claims in favor of U.S. Silica and continued compliance with the non-compete and non-solicitation provisions contained in his employment agreement.

Change in Control Severance Plan

U.S. Silica maintains the U.S. Silica Holdings, Inc. Change in Control Severance Plan, as amended from time to time (the “CIC Plan”). All executive officers of U.S. Silica are eligible to participate in the CIC Plan.

The CIC Plan provides certain benefits if the executive officer experiences a separation from service as a result of an involuntary termination of employment without cause or resignation for good reason, in either case within 24 months immediately following a change in control of U.S. Silica, which includes the Merger. If such events occur and the named executive officer has signed a general release of claims in favor of the Company, the CIC Plan provides the following benefits to the executive officers: (a) a lump sum payment equal to 1.5 times the sum of (i) the executive officer’s base salary as of the termination date (or, if greater, the salary in effect on the first occurrence of the change in control) and (ii) the executive officer’s target annual cash bonus for the year in which the termination occurs (or, if greater, the target annual cash bonus in effect as of the occurrence of the change in control); (b) a prorated annual bonus for the fiscal year in which the termination of employment occurs at the target level based on the number of days the executive officer was employed during the year; and (c) continuation of group health insurance coverage for the executive officer and the executive officer’s eligible dependents pursuant to COBRA during the 18-month period following the executive officer’s termination of employment.

If an executive officer has a separate agreement with U.S. Silica that provides for specific severance and benefits in connection with a termination of employment following a change in control, such as Mr. Shinn, the payments and benefits provided by the CIC Plan will be reduced by the payments and benefits under the individual severance agreement.

If the severance payments under the CIC Plan would trigger an excise tax under Sections 280G and 4999 of the Code, the severance payments would be reduced to a level at which the excise tax is not triggered, unless the executive officer would receive a greater amount without such reduction after applicable excise, federal, and/or state taxes.

In the event of an involuntary termination without cause not involving a change in control, Messrs. Hough, Ussery and Carusona and Ms. Russell are each entitled to cash severance equal to 12 months of base salary and reimbursement of the monthly premium for COBRA healthcare coverage for 12 months in exchange for the executive officer executing a standard release in favor of the Company. Each severance arrangement involving an executive officer is subject to the Compensation Committee’s review and approval at the time of termination.

For an estimate of the value of the payments and benefits described above that would be payable to the named executive officers upon a qualifying termination in connection with the Merger, see “—Named Executive Officer Golden Parachute Compensation” below. If Mr. Moreau, our only executive officer not discussed in “—Named Executive Officer Golden Parachute Compensation” below, experiences an involuntary termination of employment without cause or resignation for good reason in connection with the Merger, he would be entitled to the following estimated severance benefits under the CIC Plan (based on an assumed closing date of the Merger and qualifying termination on May 23, 2024): (i) a cash severance payment in the amount of $1,265,250, (ii) a prorated annual bonus in the amount of $153,113 and (iii) continued COBRA health coverage in the amount of $43,198.

70

Retention Program

In connection with the Merger, the Company and Parent agreed that prior to the closing date of the Merger, the Company and Parent will work together in good faith on establishing a process to grant cash-based retention awards to selected employees. The granting of any such awards and details of the process will be determined by mutual agreement of the Company and Parent, including but not limited to the criteria to select award recipients, amounts of awards and the terms of awards. It has not yet been determined whether or not any executive officers of the Company will receive cash-based retention awards.

Continuing Employees

The Merger Agreement provides that from the Effective Time until 12 months following the Effective Time, each employee of U.S. Silica and any of its subsidiaries as of immediately prior to the Effective Time (each, a “Continuing Employee”) will receive (i) an annual base salary or wage rate and a target short-term incentive compensation opportunity (including bonus and commission) that, in each case, is not less favorable than was provided to such Continuing Employee immediately prior to the Effective Time, (ii) for each Continuing Employee who (A) participated in U.S. Silica’s annual equity incentive program prior to the Effective Time and (B) is not invited to participate in the management equity incentive program maintained by Parent or its affiliate following closing, a target cash-based incentive compensation opportunity that is substantially equivalent to the target annual equity award opportunity provided to such Continuing Employee prior to closing, and (iii) other compensation and benefits (excluding equity-based or other long-term incentive, retention, change in control, or similar one-time or special benefits or arrangements, non-qualified deferred compensation, postretirement health and welfare benefits, and defined benefit pension benefits) that are substantially equivalent in the aggregate to those provided to such Continuing Employees immediately prior to the Effective Time. The Merger Agreement further provides that the Surviving Corporation will provide to each Continuing Employee whose employment is involuntarily terminated without cause by U.S. Silica during the one-year period following the Effective Time, severance benefits no less favorable than the severance benefits that would have been provided to the Continuing Employee under U.S. Silica’s severance arrangements in effect immediately prior to the Effective Time. With respect to benefit plans maintained by Parent and its subsidiaries, including the Surviving Corporation, for all purposes, including determining eligibility to participate, level of benefits, vesting and benefit accruals, each Continuing Employee’s service with U.S. Silica or any of its subsidiaries as reflected in U.S. Silica records will be treated as service with Parent or any of its subsidiaries (except to the extent that such recognition would result in any duplication of benefits and excluding with respect to any qualified or non-qualified defined benefit plans, non-qualified deferred compensation and post-termination or retiree health or welfare benefits).

Potential Compensation Arrangements with Parent

Any of the executive officers of U.S. Silica who become officers or employees or who otherwise are retained to provide services to Parent or its affiliates may, prior to, on, or following the Effective Time, enter into new compensation arrangements with Parent or its affiliates. In particular, such executive officers may be eligible to participate in a management equity incentive plan sponsored by Parent or its affiliates following the Effective Time. It is currently expected that participants in the plan will have the opportunity to co-invest and be granted profits interests subject to time-based and/or performance-based vesting conditions. As of the date of this proxy statement, no new individualized compensation arrangements between U.S. Silica’s executive officers and Parent or its affiliates have been established.

Named Executive Officer Golden Parachute Compensation

In accordance with Item 402(t) of Regulation S-K promulgated by the SEC, the table below sets forth the compensation that is based on, or otherwise relates to, the Merger that may be paid or become payable to each of U.S. Silica’s named executive officers in connection with the Merger. For further information regarding this compensation, see “—Treatment of Equity and Equity-Based Awards” and “—Payments and Benefits Upon Termination at or Following a Change in Control” on pages 67 and 69 of this proxy statement, respectively.

71

Under the applicable SEC rules, U.S. Silica’s named executive officers (each, an “NEO”) for this purpose are required to consist of the named executive officers for whom executive compensation disclosures were required in U.S. Silica’s most recent summary compensation table, as was included in U.S. Silica’s most recent proxy statement filed with the SEC, who are:

The amount of payments and benefits that each NEO would receive (on a pre-tax basis), as set forth in the table below, is based on the following assumptions:

The amounts below do not include the value of benefits which the NEOs are already entitled to or vested in as of the assumed date of the Merger without regard to the occurrence of a change in control, and do not reflect any possible reductions under the Section 280G “net-better” cutback provisions included in the CIC Plan. In addition, these amounts do not include any other incentive award grants, issuances or forfeitures that may be made or occur, or future dividends or dividend equivalents that may be accrued, prior to the completion of the Merger. The amounts shown are estimates of amounts that would be payable to the NEOs based on multiple assumptions that may or may not actually occur, including assumptions described in this proxy statement. Some of the assumptions are based on information not currently available. As a result of the foregoing assumptions,

72

which may or may not actually occur or be accurate on the relevant date, including the assumptions described in the footnotes to the table, the actual amounts, if any, to be received by an NEO may materially differ from the amounts set forth below.

Mr. Merril, former Chief Financial Officer of U.S. Silica, was terminated by U.S. Silica without cause effective as of October 20, 2023 (the “Separation Date”). In connection with his termination, U.S. Silica entered into a separation agreement with Mr. Merril on November 17, 2023 (the “Separation Agreement”), pursuant to which Mr. Merril received the following payments and benefits: (a) a lump sum cash payment equal to the amount of his annual base salary ($440,000), (b) payment or reimbursement of 100% of the group health insurance premiums under COBRA for 12 months following the Separation Date or, if earlier, until Mr. Merril is no longer eligible to receive coverage under COBRA, (c) eligibility to participate in the U.S. Silica 2023 annual cash incentive bonus plan ($341,325), and (d) incremental service credit for the purposes of prorated vesting of previously issued equity awards, including (i) accelerated vesting of his unvested Company RSUs that were scheduled to vest through February 2024 to which he otherwise would have been entitled and (ii) a prorated portion of each outstanding Company PSU award will continue to remain outstanding and eligible to vest until the applicable performance results have been certified and may become vested or forfeited based on actual performance over the entire performance period in accordance with the otherwise applicable performance vesting conditions set forth in each applicable award agreement. In exchange for the benefits granted to him pursuant to the Separation Agreement, Mr. Merril executed a general release of claims in favor of the Company and agreed to continued compliance with the non-compete and nonsolicitation provisions to which he is subject.

Golden Parachute Compensation

73

The estimated value of each such equity award is shown in the following table. As discussed above, these calculations assume, among other things, the closing date of the Merger is May 23, 2024 (which is the assumed date solely for purposes of this golden parachute compensation disclosure).

Financing of the Merger

The consummation of the Merger is not conditioned on Parent’s receipt of any financing. Parent plans to fund the Merger Consideration with committed Equity Financing and Debt Financing, as described below.

Pursuant to the Equity Commitment Letter, the Equity Investors have committed, severally but not jointly, to contribute or cause to be contributed to Parent at the closing of the Merger an aggregate amount in cash equal to $1.15 billion, subject to the terms and conditions of the Equity Commitment Letter.

In addition, Parent obtained a Debt Commitment Letter for (i) a $1.1 billion Term Facility and (ii) a $175 million senior secured revolving credit facility (not all of which such revolving credit facility is expected to be drawn at the closing of the Merger). In lieu of a portion of the Term Facility, Parent may issue, at its option in accordance with the terms and provisions of the Debt Commitment Letter and the fee letter executed in connection therewith, senior secured notes in a Rule 144A or other private placement yielding up to $350 million in aggregate gross cash proceeds. The availability of the Debt Financing is subject to customary conditions precedent as limited by the “certain funds provision” provided in the Debt Commitment Letter.

The proceeds of the debt financing will be used (i) to finance, in part, the payment of the amounts payable under the Merger Agreement; (ii) to repay certain existing indebtedness of U.S. Silica, including U.S. Silica’s credit agreement; (iii) in the case of the revolving facility, for general corporate purposes and (iv) to pay related fees and expenses.

74

As of the last practicable date before the printing of this proxy statement, the Debt Commitment Letter remains in effect, and Parent has not notified us of any plans to utilize financing in lieu of the financing described above. The definitive documentation governing the debt financing contemplated by the Debt Commitment Letter has not been finalized and, accordingly, the actual terms of the debt financing may differ from those described in this proxy statement; provided that such final terms shall be subject to the “certain funds provision” provided in the Debt Commitment Letter in all respects.

Limited Guarantee

Concurrently with the execution of the Merger Agreement, the Guarantors entered into the Limited Guarantee in favor of U.S. Silica, pursuant to which the Guarantors have agreed to guarantee, up to an aggregate cap of $90,300,000 and subject to certain terms and conditions set forth in the Limited Guarantee, the payment and performance of each of (but never more than one of clause (i) or (iii)) the following obligations of Parent following the valid termination of the Merger Agreement: (i) the termination fee payable by Parent under certain circumstances, if, when and as due, as well as up to $2,000,000 in costs incurred by U.S. Silica in collecting the termination fee and interest from the date the termination fee is required to be paid, if applicable; (ii) up to $1,000,000 in certain expense reimbursement or indemnity obligations that may be owed by Parent in connection with U.S. Silica’s cooperation efforts for the debt financing and transition planning; and (iii) up to $87,300,000 in recovery for damages (solely to the extent proven) as a result of Parent’s willful and material breach or fraud before the closing with respect to Parent’s representations, warranties, covenants or other agreements in the Merger Agreement, in each case, on the terms and subject to the conditions set forth in the Merger Agreement.

Appraisal Rights

General

If the Merger is consummated, record holders and beneficial owners of Dissenting Shares shall be entitled to receive such consideration as shall be determined pursuant to Section 262 of the DGCL.

The following discussion is not a complete statement of the law pertaining to appraisal rights under the DGCL and is qualified in its entirety by the full text of Section 262 of the DGCL, which is accessible, without subscription or cost, at the following publicly available website: https://delcode.delaware.gov/title8/c001/sc09/index.html#262 and incorporated by reference herein. The following summary does not constitute any legal or other advice and does not constitute a recommendation that stockholders exercise their appraisal rights under Section 262. All references in Section 262 and in this summary to (i) a “stockholder” are to the record holder of Shares unless otherwise expressly noted therein or herein, (ii) “beneficial owner” are to a person who is the beneficial owner of Shares held either in voting trust or by a nominee on behalf of such person unless otherwise expressly noted therein or herein, and (iii) a “person” are to an individual, corporation, partnership, unincorporated association or other entity.

Under Section 262, if the Merger is consummated, stockholders and beneficial owners who (a) properly deliver a written demand for appraisal of their Shares before the taking of the vote on the Merger Proposal, (b) do not submit a proxy or otherwise vote in favor of the Merger, (c) continuously hold of record or beneficially own, as applicable, such Shares upon the making of a demand under clause (a) through the Effective Time, (d) do not thereafter withdraw their demand for appraisal or otherwise lose their appraisal rights in each case in accordance with the DGCL and (e) otherwise meet the criteria and strictly follow the procedures set forth in Section 262, will be entitled to have their Shares appraised by the Delaware Court of Chancery and to receive in lieu of the Merger Consideration payment in cash of the amount determined by the Delaware Court of Chancery to be the “fair value” of the Shares, exclusive of any element of value arising from the accomplishment or expectation of the Merger, together with interest, if any, to be paid on the amount determined to be fair value as determined by the Delaware Court of Chancery (subject, in the case of interest payments, to any voluntary cash payments made by the Surviving Corporation pursuant to subsection (h) of Section 262). Unless the Delaware Court of Chancery, in its discretion, determines otherwise for good cause shown, interest on an appraisal award from the Effective Time through the date the judgment is paid will be compounded quarterly and will accrue at five percent (5%)

75

over the Federal Reserve discount rate (including any surcharge) as established from time to time during such period; provided that, if at any time before the Delaware Court of Chancery enters judgment in the appraisal proceeding, the Surviving Corporation pays to each stockholder entitled to appraisal an amount in cash, interest will accrue after the time of such payment only on the amount that equals the sum of (1) the difference, if any, between the amount so paid and the “fair value” of the Shares as determined by the Delaware Court of Chancery and (2) any interest accrued prior to the time of such voluntary payment, unless paid at such time. The Surviving Corporation is under no obligation to make such voluntary cash payment prior to such entry of judgment. Stockholders and beneficial owners who are considering seeking appraisal should be aware that the fair value of their Shares as determined pursuant to Section 262 of the DGCL could be more than, the same as or less than the Merger Consideration payable pursuant to the Merger Agreement if they did not seek appraisal of their Shares.

Under Section 262 of the DGCL, where a merger agreement is to be submitted for approval and adoption at a meeting of stockholders, the corporation, not less than 20 days prior to the meeting, must notify each of its stockholders who was such on the record date for notice of such meeting with respect to shares for which appraisal rights are available that appraisal rights are available and include in the notice either a copy of Section 262 or information directing the stockholders to a publicly available electronic resource at which Section 262 may be accessed without subscription or cost. This proxy statement constitutes U.S. Silica’s notice to stockholders that appraisal rights are available in connection with the Merger, and the full text of Section 262 of the DGCL may be accessed, without subscription or cost, at the following publicly available website: https://delcode.delaware.gov/title8/c001/sc09/index.html#262. In connection with the Merger, any stockholder or beneficial owner who wishes to exercise appraisal rights or who wishes to preserve such person’s right to do so should review the following summary and Section 262 of the DGCL carefully. Failure to strictly comply with the requirements of Section 262 in a timely and proper manner will result in the loss of appraisal rights under the DGCL. In addition, the Delaware Court of Chancery will dismiss appraisal proceedings as to all stockholders and beneficial owners who assert appraisal rights unless (a) the total number of Shares held by stockholders or beneficial owners who have become entitled to appraisal rights as determined by the Delaware Court of Chancery exceeds one percent (1%) of the outstanding Shares eligible for appraisal or (b) the value of the aggregate Merger Consideration i for such Shares entitled to appraisal exceeds $1 million. Because of the complexity of the procedures for exercising the right to seek appraisal of Shares, U.S. Silica believes that if a stockholder or beneficial owner is considering exercising appraisal rights, that person should seek the advice of legal counsel. A stockholder or beneficial owner who loses his, her, its or their appraisal rights will be entitled to receive the Merger Consideration as described in the Merger Agreement upon surrender of the certificates that formerly represented such Shares.

Stockholders and beneficial owners wishing to exercise the right to seek an appraisal of their Shares must fully comply with Section 262 of the DGCL, which means doing, among other things, ALL of the following:

76

If you fail to comply with any of these conditions and the Merger is completed, you will be entitled to receive the Merger Consideration, but you will have no appraisal rights with respect to your Shares.

Making a Written Demand

Any stockholder or beneficial owner wishing to exercise appraisal rights must deliver to U.S. Silica, before the vote on the Merger Proposal at the Special Meeting, a written demand for the appraisal of the stockholder’s or beneficial owner’s Shares. The person making the written demand must be a stockholder of record or a beneficial owner, as applicable, on the date the written demand for appraisal is made, and such person must continue to hold or beneficially own, respectively, the Shares as to which such demand relates through the effective date of the Merger.

A person wishing to exercise appraisal rights must not vote or submit a proxy in favor of the Merger Proposal either virtually during the Special Meeting or by proxy. In the case of a holder of record of Shares, a proxy that is submitted and does not contain voting instructions will, unless revoked, be voted in favor of the Merger Proposal, and it will cause a stockholder to lose the stockholder’s right to appraisal and will nullify any previously delivered written demand for appraisal. Therefore, a stockholder who submits a proxy and who wishes to exercise appraisal rights must submit a proxy containing instructions to vote against the Merger Proposal or abstain from voting on the Merger Proposal. In the case of a beneficial owner, brokers, banks and other nominees that hold Shares in “street name” for their customers do not have discretionary authority to vote those Shares on the Merger Proposal without specific voting instructions from the beneficial owner on such proposal, but such brokers, banks or other nominees will vote such Shares as instructed if the beneficial owner provides such instructions. If a beneficial owner of Shares held in “street name” instructs such person’s broker, bank, trust, or other nominee to vote such person’s Shares in favor of the Merger Proposal, and does not revoke such instruction prior to the vote on the Merger Proposal, then such Shares will be voted in favor of the approval and adoption of the Merger Agreement, and it will cause such beneficial owner to lose his, her, its or their right to appraisal and will nullify any previously delivered written demand for appraisal. Therefore, a beneficial owner who wishes to exercise appraisal rights must either not provide any instructions to such person’s broker, bank, trust, or other nominee how to vote on the Merger Proposal or must instruct such broker, bank, trust, or other nominee to vote against the approval and adoption of the Merger Agreement or abstain from voting on such proposal. Neither voting against the Merger Proposal nor abstaining from voting or failing to vote on the Merger Proposal will, in and of itself, constitute a written demand for appraisal satisfying the requirements of Section 262 of the DGCL. The written demand for appraisal must be in addition to and separate from any proxy or vote on the Merger Proposal. A proxy or vote against the Merger Proposal will not constitute a demand. A stockholder’s or beneficial owner’s failure to make the written demand prior to the taking of the vote on the Merger Proposal at the Special Meeting will cause such person to lose its appraisal rights in connection with the Merger.

A demand for appraisal made by a stockholder or beneficial owner should be executed by or on behalf of the holder of record or beneficial owner, as applicable, and must reasonably inform U.S. Silica of the identity of such stockholder or beneficial owner. In addition, in the case of a demand for appraisal of such beneficial owner, the demand must also (a) reasonably identify the holder of record of the Shares for which the demand is made, (b) be accompanied by documentary evidence of the beneficial owner’s ownership of stock (such as a brokerage or securities account statement containing such information or a letter from the broker or other record holder of such Shares confirming such information) and a statement that such documentary evidence is a true and correct copy of what it purports to be and (c) provide an address at which such beneficial owner consents to receive notices given by the Surviving Corporation under Section 262 of the DGCL and the verified list required by subsection (f) of Section 262 (discussed further below). Whether made by a stockholder or a beneficial owner, a written demand for appraisal must state that the person intends thereby to demand appraisal of the person’s

77

Shares in connection with the Merger. If the Shares are held of record or beneficially owned in a fiduciary capacity, such as by a trustee, guardian or custodian, such demand must be executed by or on behalf of such holder of record or beneficial owner in such capacity, and if the Shares are held of record or beneficially owned by more than one person, such as in a joint tenancy or a tenancy in common, the demand should be executed by or on behalf of all such joint holders of record or beneficial owners. An authorized agent, including an authorized agent for two or more joint stockholders or beneficial owners, may execute a demand for appraisal on behalf of a holder of record or beneficial owner; however, the agent must identify the record holder or holders or beneficial owner or owners, respectively, and should expressly disclose that, in executing the demand, the agent is acting as agent for the record holder or holders or beneficial owner or owners, as applicable.

All written demands for appraisal pursuant to Section 262 of the DGCL should be mailed or delivered to:

U.S. Silica Holdings, Inc.

24275 Katy Freeway, Suite 600

Katy, TX 77494

Attention: Corporate Secretary

Any stockholder or beneficial owner who has delivered a written demand to U.S. Silica and who has not commenced an appraisal proceeding or joined that proceeding as a named party may withdraw his or her or its demand for appraisal in respect of some or all of such person’s Shares and accept the Merger Consideration with respect to the Shares subject to the withdrawal by delivering to the Surviving Corporation a written withdrawal of the demand for appraisal within 60 days after the Effective Time. However, any such attempt to withdraw the demand made more than 60 days after the Effective Time will require written approval of the Surviving Corporation. No appraisal proceeding in the Delaware Court of Chancery will be dismissed as to any person without the approval of such court and such approval may be conditioned upon such terms as the Delaware Court of Chancery deems just including without limitation, a reservation of jurisdiction for any application to the Delaware Court of Chancery made under subsection (j) of Section 262; provided, however, that this shall not affect the right of any person who has not commenced an appraisal proceeding or joined that proceeding as a named party to withdraw such person’s demand for appraisal in respect of some or all of such person’s Shares and accept the Merger Consideration with respect to the Shares subject to the withdrawal within 60 days after the Effective Time.

Notice by the Surviving Corporation

If the Merger is consummated, within 10 days after the Effective Time, the Surviving Corporation will notify each stockholder who has made a written demand for appraisal pursuant to Section 262 and who has not voted in favor of the Merger Proposal, and any beneficial owner who has properly demanded appraisal in such person’s name pursuant to Section 262 of the DGCL, of the date that the Merger has become effective.

Filing a Petition for Appraisal

Within 120 days after the Effective Time, the Surviving Corporation or any stockholder or beneficial owner who has complied with Section 262 of the DGCL and is entitled to appraisal rights under Section 262 may commence an appraisal proceeding by filing a petition in the Delaware Court of Chancery, with a copy served on the Surviving Corporation in the case of a petition filed by a stockholder, demanding a determination of the fair value of the Shares held by all persons entitled to appraisal. If a petition for appraisal is not timely filed, then the right to an appraisal will cease. The Surviving Corporation is under no obligation, and has no present intention, to file such a petition, and stockholders and beneficial owners should not assume that the Surviving Corporation will file a petition or initiate any negotiations with respect to the fair value of the Shares. Accordingly, any stockholders or beneficial owners of Shares who desire to have their Shares appraised by the Delaware Court of Chancery should assume that they will be responsible for filing a petition for appraisal with the Delaware Court of Chancery in the manner prescribed in Section 262. The failure of a stockholder or beneficial owner to file such a petition for appraisal within the period specified in Section 262 will nullify the person’s previous written demand for appraisal.

78

Within 120 days after the Effective Time, any stockholder or beneficial owner who has complied with the requirements for the exercise of appraisal rights, will be entitled, upon written request, to receive from the Surviving Corporation a statement setting forth the aggregate number of Shares not voted in favor of the Merger Proposal and with respect to which U.S. Silica received demands for appraisal, and the aggregate number of stockholders or beneficial owners holding or owning such Shares (provided that, in the case of a demand made by a beneficial owner in such person’s name, the record holder of such Shares shall not be considered a separate stockholder holding such Shares for purposes of such aggregate number). The Surviving Corporation must mail this statement to the requesting person within 10 days after receipt of the written request for such a statement or within 10 days after the expiration of the period for delivery of demands for appraisal, whichever is later.

If a petition for an appraisal is duly filed by a stockholder or beneficial owner and a copy thereof is served upon the Surviving Corporation, the Surviving Corporation will then be obligated within 20 days after such service to file in the office of the Delaware Register in Chancery in which the petition was filed a duly verified list containing the names and addresses of all persons who have demanded appraisal of their Shares and with whom agreements as to the value of their Shares have not been reached. After notice to the stockholders and beneficial owners as may be required by the Delaware Court of Chancery, the Delaware Court of Chancery will determine those persons who have complied with Section 262 of the DGCL and who have become entitled to appraisal rights thereunder. The Delaware Court of Chancery may require the persons who demanded appraisal of their Shares and who hold stock represented by certificates to submit their stock certificates to the Register in Chancery for notation thereon of the pendency of the appraisal proceedings, and if any person fails to comply with the direction, the Delaware Court of Chancery may dismiss the proceedings as to such person.

Determination of Fair Value

After determining the persons entitled to appraisal, the appraisal proceeding will be conducted in accordance with the rules of the Delaware Court of Chancery, including any rules specifically governing appraisal proceedings. The Delaware Court of Chancery will determine the “fair value” of the Shares, exclusive of any element of value arising from the accomplishment or expectation of the Merger, together with interest, if any, to be paid upon the amount determined to be the fair value. In determining fair value, the Delaware Court of Chancery will take into account all relevant factors. In Weinberger v. UOP, Inc., the Supreme Court of Delaware discussed the factors that could be considered in determining fair value in an appraisal proceeding, stating that “proof of value by any techniques or methods which are generally considered acceptable in the financial community and otherwise admissible in court” should be considered, and that “[f]air price obviously requires consideration of all relevant factors involving the value of a company.” The Delaware Supreme Court stated that, in making this determination of fair value, the court must consider market value, asset value, dividends, earnings prospects, the nature of the enterprise and any other facts that could be ascertained as of the date of the Merger that throw any light on future prospects of the merged corporation. The Delaware Supreme Court has indicated that transaction price is one of the relevant factors the Delaware Court of Chancery may consider in determining “fair value” and that absent deficiencies in the sale process the transaction price should be given “considerable weight.” Section 262 of the DGCL provides that fair value is to be “exclusive of any element of value arising from the accomplishment or expectation of the merger.” In Cede & Co. v. Technicolor, Inc., the Supreme Court of Delaware stated that such exclusion is a “narrow exclusion [that] does not encompass known elements of value,” but which rather applies only to the speculative elements of value arising from such accomplishment or expectation. In Weinberger, the Supreme Court of Delaware also stated that “elements of future value, including the nature of the enterprise, which are known or susceptible of proof as of the date of the merger and not the product of speculation, may be considered.”

Stockholders and beneficial owners considering seeking appraisal should be aware that the fair value of their Shares as so determined by the Delaware Court of Chancery could be more than, the same as or less than the consideration they would receive pursuant to the Merger if they did not seek appraisal of their Shares and that an opinion of an investment banking firm as to the fairness from a financial point of view of the consideration payable in a merger is not an opinion as to, and does not in any manner address, fair value under Section 262 of

79

the DGCL. Although U.S. Silica believes that the Merger Consideration is fair, no representation is made as to the outcome of the appraisal of fair value as determined by the Delaware Court of Chancery, and stockholders and beneficial owners should recognize that such an appraisal could result in a determination of a value higher or lower than, or the same as, the Merger Consideration. Neither U.S. Silica nor Parent anticipates offering more than the Merger Consideration to any person exercising appraisal rights. Each of U.S. Silica and Parent reserves the right to assert, in any appraisal proceeding, that for purposes of Section 262 of the DGCL, the “fair value” of a Share is less than the Merger Consideration.

Unless the Delaware Court of Chancery in its discretion determines otherwise for good cause shown, interest from the Effective Time through the date of payment of the judgment will be compounded quarterly and will accrue at five percent (5%) over the Federal Reserve discount rate (including any surcharge) as established from time to time during the period between the Effective Time and the date of payment of the judgment; provided that if at any time before the Delaware Court of Chancery enters judgment in the appraisal proceeding, the Surviving Corporation pays to each stockholder entitled to appraisal an amount in cash, interest will accrue after the time of such payment only on the amount that equals the sum of (a) the difference, if any, between the amount so paid and the “fair value” of the Shares as determined by the Delaware Court of Chancery and (b) any interest accrued prior to the time of such voluntary payment, unless paid at such time. The Surviving Corporation is under no obligation to make such voluntary cash payment prior to such entry of judgment. The costs of the appraisal proceedings (which do not include attorneys’ fees or the fees and expenses of experts) may be determined by the Delaware Court of Chancery and taxed upon the parties as the Delaware Court of Chancery deems equitable under the circumstances. Upon application of a person whose name appears on the list filed by the Surviving Corporation of persons who participated in the proceeding and incurred expenses in connection therewith, the Delaware Court of Chancery may order that all or a portion of the expenses, including, without limitation, reasonable attorneys’ fees and the fees and expenses of experts, be charged pro rata against the value of all Shares entitled to appraisal not dismissed pursuant to subsection (k) of Section 262 or subject to such an award pursuant to a reservation of jurisdiction under Subsection (k) of Section 262. In the absence of such an order, each party bears its own expenses.

If any stockholder or beneficial owner who demands appraisal of his, her, its, or their Shares under Section 262 of the DGCL fails to perfect, or loses or successfully withdraws, such person’s right to appraisal, the person’s Shares will be deemed to have been converted at the Effective Time into the Merger Consideration, less applicable withholding taxes. A person will fail to perfect, or effectively lose or withdraw, the person’s right to appraisal if no petition for appraisal is filed within 120 days after the Effective Time or if the stockholder or beneficial owner, as applicable, delivers to the Surviving Corporation a written withdrawal of the person’s demand for appraisal in respect to some or all of such person’s Shares and an acceptance of the Merger Consideration with respect to the Shares subject to withdrawal in accordance with Section 262.

From and after the Effective Time, no person who has demanded appraisal rights will be entitled to vote their Shares for any purpose, or to receive payment of dividends or other distributions on the Shares, except dividends or other distributions on the person’s Shares, if any, payable to stockholders of record as of a time prior to the Effective Time.

Failure to comply strictly with all of the procedures set forth in Section 262 of the DGCL may result in the loss of statutory appraisal rights. Consequently, any stockholder or beneficial owner wishing to exercise appraisal rights is encouraged to consult legal counsel before attempting to exercise those rights.

STOCKHOLDERS AND BENEFICIAL OWNERS WHO VOTE SHARES IN FAVOR OF THE APPROVAL AND ADOPTION OF THE MERGER AGREEMENT WILL NOT BE ENTITLED TO EXERCISE APPRAISAL RIGHTS WITH RESPECT THERETO BUT, RATHER, WILL RECEIVE THE MERGER CONSIDERATION.

To the extent there are any inconsistences between the foregoing summary, on the one hand, and Section 262 of the DGCL, on the other hand, Section 262 of the DGCL will govern.

80

Accounting Treatment

The Merger will be accounted for as a “purchase transaction” for financial accounting purposes.

Material U.S. Federal Income Tax Consequences of the Merger

The following discussion is a summary of the material U.S. federal income tax consequences of the Merger to U.S. holders and non-U.S. holders (each as defined below) of Shares who receive cash in exchange for Shares pursuant to the Merger. This discussion is for general informational purposes only and does not purport to be a complete analysis of all potential tax consequences of the Merger. The tax consequences of the Merger under U.S. federal tax laws other than those pertaining to income tax, such as estate and gift tax laws, and any applicable state, local and non-U.S. tax laws are not discussed herein. This discussion is based on the Code, the Treasury Regulations promulgated thereunder, judicial decisions and published rulings and administrative pronouncements of the IRS, in each case in effect as of the date of this proxy statement. These authorities may change or be subject to differing interpretations, and any such change or differing interpretation may be applied retroactively in a manner that could affect the accuracy of the statements and conclusions set forth in this discussion. The U.S. federal income tax laws are complex and subject to varying interpretation. We have not sought, and do not intend to seek, any rulings from the IRS with respect to the statements made and the conclusions reached in the following discussion. There can be no assurance the IRS or a court will not take a contrary position to that discussed below regarding the tax consequences of the Merger.

This discussion is limited to U.S. Silica Stockholders who hold such Shares as “capital assets” within the meaning of Section 1221 of the Code (generally, property held for investment). This discussion does not address all U.S. federal income tax consequences that may be relevant to a holder’s particular circumstances, including the impact of the Medicare contribution tax on net investment income and the alternative minimum tax. In addition, this discussion does not address the U.S. federal income tax consequences to holders subject to special rules under the U.S. federal income tax laws, including, without limitation:

81

This discussion also does not address the U.S. federal income tax consequences to U.S. Silica Stockholders who exercise appraisal rights in connection with the Merger under the DGCL.

If an entity or arrangement classified as a partnership for U.S. federal income tax purposes holds Shares, the tax treatment of a partner in the partnership will generally depend on the status of the partner, the activities of the partnership and certain determinations made at the partner level. Accordingly, partnerships holding Shares and partners in such partnerships should consult their tax advisors regarding the U.S. federal income tax consequences of the Merger to them.

THIS DISCUSSION IS FOR INFORMATION PURPOSES ONLY AND IS NOT TAX OR LEGAL ADVICE. U.S. SILICA STOCKHOLDERS SHOULD CONSULT THEIR TAX ADVISORS WITH RESPECT TO THE U.S. FEDERAL INCOME TAX CONSEQUENCES OF THE MERGER TO THEM IN LIGHT OF THEIR PARTICULAR CIRCUMSTANCES, AS WELL AS ANY TAX CONSEQUENCES OF THE MERGER ARISING UNDER THE U.S. FEDERAL TAX LAWS OTHER THAN THOSE PERTAINING TO INCOME TAX, INCLUDING ESTATE OR GIFT TAX LAWS, OR UNDER ANY STATE, LOCAL OR NON-U.S. TAX LAWS OR UNDER ANY APPLICABLE INCOME TAX TREATY.

Tax Consequences to U.S. Holders

Definition of a U.S. Holder

For purposes of this discussion, a “U.S. holder” is any beneficial owner of Shares that, for U.S. federal income tax purposes, is or is treated as any of the following:

Effect of the Merger

The receipt of cash by a U.S. holder in exchange for Shares in the Merger will generally be a taxable transaction for U.S. federal income tax purposes. The amount of any taxable gain or loss realized by a U.S. holder who receives cash for Shares in the Merger will generally equal the difference, if any, between the amount of cash received for such Shares (determined before the deduction of any applicable withholding taxes) and the U.S. holder’s adjusted tax basis in such Shares. A U.S. holder’s adjusted tax basis in a Share will generally be equal to the amount the U.S. holder paid for such Share. The amount and character of such gain or loss and the holding period of Shares will be determined separately for each block of Shares (that is, Shares acquired at the same cost in a single transaction) exchanged for cash in the Merger. Any gain or loss realized by a U.S. holder upon the receipt of cash in exchange for a Share in the Merger will generally be capital gain or loss, and will be long-term capital gain or loss if the U.S. holder has held such Share for more than one year at the Effective Time. Otherwise, such gain or loss will be short-term capital gain or loss. Short-term capital gain is subject to U.S. federal income tax at the same rates as ordinary income. Long-term capital gains recognized by certain non-corporate U.S. holders, including individuals, are generally taxable at a lower rate. The deductibility of net capital losses is subject to limitations.

82

Information Reporting and Backup Withholding

Payments made to a U.S. holder in exchange for Shares pursuant to the Merger may be subject to information reporting to the IRS and backup withholding (currently at a rate of 24%). Such payments will not be subject to backup withholding if the U.S. holder (i) completes and returns to the paying agent a properly executed IRS Form W-9 included in the letter of transmittal certifying that the U.S. holder is a United States person, the taxpayer identification number provided is correct and that the U.S. holder is not subject to backup withholding or (ii) otherwise establishes an exemption. Certain U.S. holders (including corporations) are not subject to backup withholding or information reporting.

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against the U.S. holder’s U.S. federal income tax liability, if any, provided the required information is timely furnished to the IRS.

U.S. holders should consult their tax advisors regarding their qualification for an exemption from backup withholding and the procedures for obtaining such an exemption.

Tax Consequences to Non-U.S. Holders

Definition of a Non-U.S. Holder

For purposes of this discussion, a “non-U.S. holder” is a beneficial owner of Shares that is neither a U.S. holder nor an entity or arrangement classified as a partnership for U.S. federal income tax purposes.

Effect of the Merger

A non-U.S. holder will generally not be subject to U.S. federal income tax on any gain realized on the receipt of cash in exchange for Shares in the Merger unless any of the following situations apply:

83

Non-U.S. holders should consult their tax advisors regarding potentially applicable income tax treaties that may provide for different rules.

Information Reporting and Backup Withholding

Payments made to non-U.S. holders in exchange for Shares pursuant to the Merger may be subject to information reporting to the IRS and backup withholding (currently at a rate of 24%). A non-U.S. holder generally will not be subject to information reporting and backup withholding if the non-U.S. holder (i) provides the paying agent with a properly executed IRS Form W-8BEN, IRS Form W-8BEN-E or IRS Form W-8ECI (or successor form), as the case may be, certifying under penalties of perjury the holder’s non-U.S. status (and the paying agent does not have actual knowledge or reason to know that the holder is a United States person) or (ii) otherwise establishes an exemption.

Copies of information returns that are filed with the IRS may be made available under the provisions of an applicable tax treaty or information exchange agreement to the tax authorities of the country in which the non-U.S. holder resides or is established.

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against a non-U.S. holder’s U.S. federal income tax liability, if any, provided the required information is timely furnished to the IRS.

The discussion above of material U.S. federal income tax consequences is not intended to constitute a complete description of all tax consequences relating to the Merger. This summary is for general information purposes only and is not tax or legal advice. Because individual circumstances may differ, each holder should consult their tax advisor regarding the applicability of the rules discussed above to the holder and the particular tax effects to the holder of the Merger in light of such holder’s particular circumstances, including the tax consequences arising under the U.S. federal estate or gift tax rules, or through the application of any state, local or non-U.S. tax laws or any applicable income tax treaty.

Regulatory Filings

General

U.S. Silica, Parent and Merger Sub have agreed to use their reasonable best efforts to take, or cause to be taken, all actions that are necessary, proper or advisable under the Merger Agreement and applicable law to obtain the required regulatory approval, namely the expiration or termination of the applicable waiting period under the HSR Act, and to consummate and make effective the Merger and the other transactions contemplated by the Merger Agreement as promptly as practicable. In addition, Parent and U.S. Silica have agreed to file with the FCC all forms and applications required to be filed under the Communications Act of 1934 and the rules and regulations thereunder in order to seek consent to the transfer of control of U.S. Silica’s FCC licenses to Parent, and to cooperate to take all actions necessary, proper or advisable to obtain such consent.

84

Except as prohibited by law, each of U.S. Silica, Parent and Merger Sub have agreed to use reasonable best efforts to (i) cooperate reasonably with each other in connection with filings or submissions under the HSR Act or other antitrust laws in connection with the transactions contemplated by the Merger Agreement or any investigation or other inquiry by or before a governmental entity in connection with the transactions contemplated by the Merger Agreement; (ii) promptly inform the other parties of material communications received from the FTC, the DOJ or any other similar governmental entity; (iii) consult with each other prior to taking any material position with respect to the filings under the HSR Act or other antitrust laws; (iv) permit the other parties’ legal counsel to review and discuss in advance any analyses, presentations, memoranda, briefs, arguments, opinions and proposals to be submitted to any governmental entity with respect to filings under the HSR Act; (v) coordinate with the other parties’ legal counsel in preparing and exchanging such information and promptly provide the other parties’ legal counsel with copies of all filings, presentations or material submissions made by such party with any governmental entity relating to the Merger Agreement or the transactions contemplated thereby under the HSR Act or other antitrust laws; and (vi) to the extent permitted by the governmental entity, participate in material discussions related to obtaining clearances required in connection with the transactions contemplated by the Merger Agreement. Parent will, with prior notice to and consultation of U.S. Silica, and taking U.S. Silica’s views into account in good faith, control and lead all communications and strategy on behalf of the parties relating to the HSR Act and any antitrust law.

If and to the extent necessary to obtain any approval required under the HSR Act or any antitrust law for the closing of the Merger or to avoid the entry of or have lifted or terminated any order restraining or enjoining the Merger, Parent will (i) propose, negotiate and offer to commit and to effect, by consent decree, hold separate order or otherwise, (A) the sale or other disposition of any assets or businesses of U.S. Silica and its subsidiaries; (B) behavioral limitations on the assets or businesses of U.S. Silica and its subsidiaries; and (C) the termination, modification, transfer or other action with respect to any existing relationships and contractual rights and obligations of U.S. Silica and its subsidiaries; and (ii) otherwise offer to take any action that it is capable of taking and, if the offer is accepted, take such action, that limits or affects its freedom of action. Notwithstanding the foregoing, none of Parent, Merger Sub, U.S. Silica or any of their subsidiaries is required to take any of the foregoing actions to the extent such actions would have or would reasonably be expected to have, individually or in the aggregate, a material adverse effect on the business, operations or financial condition of U.S. Silica. In addition, notwithstanding the foregoing, nothing will require Apollo or certain of its related persons or entities, or require Parent or Merger Sub to cause Apollo or any such person or entity, to take any of the foregoing actions (or any action with respect to any business, product line or asset other than of U.S. Silica and its subsidiaries).

HSR Act and U.S. Antitrust Matters

The Merger is subject to the HSR Act. Under the HSR Act and the rules and regulations promulgated thereunder by the FTC, the Merger cannot be completed until Apollo and U.S. Silica each file a notification and report form with the FTC and the Antitrust Division of the DOJ under the HSR Act and the applicable waiting period thereunder has expired or been terminated. Apollo and U.S. Silica submitted these notifications on May 10, 2024, and based on that filing date, the applicable waiting period under the HSR Act will expire on June 10, 2024, absent a request for additional information from the FTC or the DOJ pursuant to the HSR Act.

At any time before or after consummation of the Merger, notwithstanding the expiration or termination of the waiting period under the HSR Act, the FTC or the DOJ could take such action under the antitrust laws as it deems necessary or desirable in the public interest, including seeking to enjoin the completion of the Merger, seeking divestiture of substantial assets of the parties or seeking to require the parties to license, or hold separate, assets or terminate existing relationships and contractual rights. At any time before or after the completion of the Merger, and notwithstanding the expiration or termination of the waiting period under the HSR Act, any state could take such action under the antitrust laws as it deems necessary or desirable in the public interest. Such action could include seeking to enjoin the completion of the Merger or seeking divestiture of substantial assets of the parties. Private parties may also seek to take legal action under the antitrust laws under certain circumstances.

85

THE MERGER AGREEMENT

(THE MERGER PROPOSAL)

The following summary describes certain material provisions of the Merger Agreement. This summary and descriptions of the Merger Agreement elsewhere in this proxy statement are not complete and are qualified in their entirety by reference to the Merger Agreement, which is attached to this proxy statement as Annex A and incorporated into this proxy statement by reference. We encourage you to read the Merger Agreement carefully and in its entirety because this summary may not contain all the information about the Merger Agreement that is important to you. The rights and obligations of the parties are governed by the express terms of the Merger Agreement and not by this summary or any other information contained in this proxy statement.

Explanatory Note Regarding the Merger Agreement and the Summary of the Merger Agreement

The Merger Agreement and the summary of terms included in this proxy statement have been prepared to provide you with information regarding the terms of the Merger Agreement. Factual disclosures about U.S. Silica contained in this proxy statement or in U.S. Silica’s public filings with the SEC, as described in “Where You Can Find More Information” on page 126 of this proxy statement, may supplement, update or modify the factual disclosures about U.S. Silica contained in the Merger Agreement and in this summary. The representations, warranties and covenants contained in the Merger Agreement have been made solely for the purposes of the Merger Agreement and as of specific dates and solely for the benefit of parties to the Merger Agreement, and:

Except as expressly stated in the Merger Agreement, U.S. Silica Stockholders are not third-party beneficiaries under the Merger Agreement and should not rely on the representations, warranties, covenants and agreements or any descriptions thereof as characterizations of the actual state of facts or condition of U.S. Silica, Parent or Merger Sub or any of their respective affiliates or businesses. In addition, you should not rely on the covenants in the Merger Agreement as actual limitations on the respective businesses of U.S. Silica, Parent or Merger Sub because the parties may take certain actions that are either expressly permitted in the confidential disclosure schedules to the Merger Agreement or as otherwise consented to by the appropriate party, which consent may be given without notice to the public. Moreover, information concerning the subject matter of the representations and warranties, which do not purport to be accurate as of the date of this proxy statement, may have changed since the date of the Merger Agreement, and subsequent developments or new information qualifying a representation or warranty may not be included in this proxy statement. Accordingly, the representations, warranties, covenants and other provisions of the Merger Agreement or any description of such provisions should not be read alone, but instead should be read together with the information provided elsewhere in this proxy statement and in the documents incorporated by reference into this proxy statement, as well as the disclosures in U.S. Silica’s periodic and current reports, proxy statements and other documents filed with the SEC. See “Where You Can Find More Information” on page 126 of this proxy statement.

86

Effects of the Merger; Directors and Officers; Certificate of Incorporation; Bylaws

The Merger Agreement provides that, subject to the terms and conditions of the Merger Agreement, and in accordance with the DGCL, at the Effective Time, Merger Sub will be merged with and into U.S. Silica, with U.S. Silica continuing as the Surviving Corporation and as a wholly owned subsidiary of Parent from and after the Effective Time.

At the Effective Time, by virtue of the Merger and without the necessity of further action by U.S. Silica or any other entity or person, the certificate of incorporation of the Surviving Corporation will be amended and restated in its entirety in the form set forth as Exhibit A to the Merger Agreement and as so amended, shall be the certificate of incorporation of the Surviving Corporation until amended in accordance with applicable law (and in accordance with Parent’s and the Surviving Corporation’s obligations described in “The Merger—Interests of the Directors and Officers of U.S. Silica in the Merger” on page 66 of this proxy statement). The bylaws of Merger Sub in effect immediately prior to the Effective Time will be the form of bylaws of the Surviving Corporation as of the Effective Time, until amended in accordance with applicable law (and in accordance with Parent’s and the Surviving Corporation’s obligations described in “The Merger—Interests of the Directors and Officers of U.S. Silica in the Merger” on page 66 of this proxy statement).

At the Effective Time, by virtue of the Merger and without the necessity of further action by U.S. Silica or any other person, the board of directors of Merger Sub immediately prior to the Effective Time (or such other individuals designated by Parent as of the Effective Time) will become the directors of the Surviving Corporation, each to hold office, from and after the Effective Time, in accordance with the certificate of incorporation and bylaws of the Surviving Corporation until their respective successors have been duly elected, designated or qualified, or until their earlier death, resignation or removal in accordance with the certificate of incorporation and bylaws of the Surviving Corporation. The officers of U.S. Silica immediately prior to the Effective Time, from and after the Effective Time, will continue as the officers of the Surviving Corporation, each to hold office in accordance with the certificate of incorporation and bylaws of the Surviving Corporation until their respective successors are duly elected, designated or qualified, or until their earlier death, resignation or removal in accordance with the certificate of incorporation and bylaws of the Surviving Corporation.

Merger Consideration

Common Stock

At the Effective Time, each Share issued and outstanding immediately prior to the Effective Time (other than Excluded Shares), will be converted automatically into the right to receive the Merger Consideration, payable to the holder in cash, without interest, subject to any applicable withholding of taxes required by law, upon surrender of the certificates or book-entry Shares (in accordance with the Merger Agreement). All Shares converted into the right to receive the Merger Consideration will be automatically cancelled and shall represent only the right to receive the Merger Consideration, in cash, without interest, subject to any applicable withholding of taxes.

Outstanding Equity Awards

At the Effective Time, each Company PSU that is outstanding immediately prior to the Effective Time will, automatically and without any action on the part of Parent, U.S. Silica or the holder thereof, vest in full and be cancelled, with the holder of such Company PSU becoming entitled to receive an amount in cash (subject to any applicable withholding taxes) equal to the product of (x) the number of Shares subject to the Company PSU immediately prior to the Effective Time, multiplied by (y) the Merger Consideration. For purposes of determining the number of Shares subject to a Company PSU immediately prior to the Effective Time: (A) in the case of TSR Company PSUs, the number of Shares will be based on the greater of the target level and the actual level of performance measured as of the Measurement Date and using the value of the Merger Consideration as U.S. Silica’s “ending stock price” for calculating performance; and (B) in the case of ACF Company PSUs, the number of Shares will be based on (1) actual performance for performance periods that have been completed as of the Measurement

87

Date, (2) the greater of the target level and the actual level of performance measured as of the Measurement Date in respect of performance periods that are ongoing as of the Measurement Date and (3) target performance in respect of performance periods that have not commenced as of the Measurement Date.

At the Effective Time, each Company RSU that is outstanding immediately prior to the Effective Time will, automatically and without any action on the part of Parent, U.S. Silica or the holder thereof, vest in full and be cancelled, with the holder of such Company RSU becoming entitled to receive an amount in cash (subject to any applicable withholding taxes) equal to the product of (x) the number of Shares subject to the Company RSU immediately prior to the Effective Time, multiplied by (y) the Merger Consideration.

At the Effective Time, each Company Option that is outstanding and unexercised immediately prior to the Effective Time will, automatically and without any action on the part of Parent, U.S. Silica or the holder thereof, be cancelled in exchange for the right to receive an amount in cash (subject to any applicable withholding taxes) equal to the product of (x) the excess, if any, of the Merger Consideration over the per Share exercise price of such Company Option, multiplied by (y) the number of Shares covered by such Company Option immediately prior to the Effective Time. If the per Share exercise price of such Company Option equals or exceeds the Merger Consideration, such Company Option shall be cancelled for no consideration.

Termination of Company Equity Plan

As of the Effective Time, the Company Equity Plan will immediately terminate and no further Company Options, Company PSUs or Company RSUs (collectively, “Company Awards”) or other awards or rights with respect to Shares will be granted thereunder. As soon as practicable (and in any event within 10 business days) following the Effective Time, Parent will, or will cause the Surviving Corporation to, pay (through its payroll system in the case of employees) all amounts payable as described above in “—Merger Consideration—Outstanding Equity Awards” to the former holders of Company Options, Company RSUs and Company PSUs, as applicable, or at such later time as required under Section 409A of the Code.

Payment for Securities; Surrender of Certificates

At or prior to the Effective Time, Parent will designate a nationally recognized bank or trust company to act as the paying agent (the identity and terms of appointment of which will be reasonably acceptable to U.S. Silica) for purposes of effecting the payment of the Merger Consideration in connection with the transactions contemplated by the Merger Agreement. Subject to the occurrence of the closing of the Merger, U.S. Silica will pay, or cause to be paid, the fees and expenses of the paying agent. At or prior to the Effective Time, Parent will deposit, or cause to be deposited, with the paying agent a cash amount that, when taken together with available cash of U.S. Silica and its subsidiaries that is deposited with the paying agent at the Effective Time, is sufficient to pay the aggregate Merger Consideration to which U.S. Silica Stockholders shall be entitled at the Effective Time pursuant to the Merger Agreement. In the event such deposited funds, when taken together with available cash of U.S. Silica and its subsidiaries that is deposited with the paying agent at the Effective Time, are insufficient to make the payments for the purposes of effecting the payment of the Merger Consideration, Parent will promptly deposit, or cause to be deposited, with the paying agent additional funds to ensure that the paying agent has sufficient funds to make such payments.

As soon as practicable after the Effective Time (and in no event later than three business days after the Effective Time), the Surviving Corporation will cause the paying agent to mail to each person that was, immediately prior to the Effective Time, a holder of record of Shares represented by a stock certificate, which Shares were converted into the right to receive the Merger Consideration at the Effective Time, a letter of transmittal and instructions for effecting the surrender of the stock certificates (or affidavits of loss in lieu of the stock certificates) in exchange for payment of the Merger Consideration. Upon surrender of a stock certificate (or affidavit of loss) to the paying agent, together with delivery of an executed letter of transmittal, the paying agent

88

will transmit to the holder of such stock certificates the Merger Consideration for each Share formerly represented by such stock certificates (subject to any applicable tax withholding), and any such stock certificate so surrendered will be cancelled.

No holder of book-entry Shares will be required to deliver a stock certificate or, in the case of holders of book-entry Shares held through The Depository Trust Company, an executed letter of transmittal to the paying agent, to receive the Merger Consideration that such holder is entitled to receive pursuant to the Merger Agreement. In lieu thereof, each holder of one or more book-entry Shares held through The Depository Trust Company whose Shares were converted into the right to receive the Merger Consideration will automatically upon the Effective Time be entitled to receive, and Parent shall cause the paying agent to pay and deliver to The Depository Trust Company or its nominee as promptly as practicable after the Effective Time, in respect of each such book-entry Share, a cash amount in immediately available funds equal to the Merger Consideration (subject to applicable withholding taxes), and such book-entry Shares will be cancelled. As soon as practicable after the Effective Time (and in no event later than three business days after the Effective Time), the Surviving Corporation will cause the paying agent to mail to each person that was, immediately prior to the Effective Time, a holder of record of book-entry Shares not held through The Depository Trust Company a letter of transmittal, which shall be in such form as Parent, U.S. Silica and the paying agent shall reasonably agree prior to the Effective Time, and instructions for returning such letter of transmittal in exchange for the Merger Consideration. Upon delivery of such letter of transmittal, in accordance with its terms and duly executed, the holder of such book-entry Shares shall be entitled to receive, in exchange for each such book-entry Share, a cash amount in immediately available funds equal to the Merger Consideration (subject to applicable withholding taxes), and such book-entry Shares so surrendered will be cancelled. Payment of the Merger Consideration with respect to book-entry Shares so surrendered will only be made to the person in whose name such book-entry Shares are registered. No interest will be paid or accrued on any amount payable upon due surrender of book-entry shares. Until paid or surrendered as contemplated by the Merger Agreement, each book-entry share will be deemed at any time after the Effective Time to represent only the right to receive the Merger Consideration in cash as contemplated by the Merger Agreement, except for book-entry shares representing Dissenting Shares, which will be deemed to represent the right to receive payment of the fair value of such Shares in accordance with and solely to the extent provided by Section 262 of the DGCL.

At the Effective Time the stock transfer books of U.S. Silica will be closed and thereafter there will be no further registration of transfers of Shares on the records of U.S. Silica. From and after the Effective Time, the holders of stock certificates and book-entry Shares outstanding immediately prior to the Effective Time will cease to have any rights with respect to such Shares, except as otherwise provided for in the Merger Agreement or by applicable law. If, after the Effective Time, stock certificates are presented to the Surviving Corporation for any reason, they will be cancelled and exchanged as provided in the Merger Agreement.

Any portion of the funds (including any interest received with respect thereto) made available to the paying agent that remains unclaimed by the holders of stock certificates or book-entry Shares on the first anniversary of the Effective Time will be returned to the Surviving Corporation or an affiliate thereof designated by the Surviving Corporation, upon demand, and any such holder of Shares who has not tendered its stock certificates or book-entry Shares for the Merger Consideration in accordance with the Merger Agreement prior to such time will thereafter look only to Parent and the Surviving Corporation (subject to abandoned property, escheat or other similar laws) for delivery of the Merger Consideration, without interest and subject to any withholding of taxes required by applicable law, in respect of such holder’s surrender of their certificates or book-entry shares. Any portion of the Merger Consideration remaining unclaimed by the holders of stock certificates or book-entry Shares immediately prior to such time as such amounts would otherwise escheat to, or become property of, any governmental entity will, to the extent permitted by applicable law, become the property of the Surviving Corporation or an affiliate thereof designated by the Surviving Corporation, free and clear of any claim or interest of any person previously entitled thereto. Notwithstanding the foregoing, none of Parent, Merger Sub, the Surviving Corporation, the paying agent or their respective affiliates will be liable to any holder of a stock certificate or book-entry Shares for Merger Consideration delivered to a public official pursuant to any applicable

89

abandoned property, escheat or similar law. Any portion of the Merger Consideration made available to the paying agent to pay for Shares for which appraisal rights have been perfected will be returned to the Surviving Corporation, upon demand.

In the event that any stock certificates shall have been lost, stolen or destroyed, the paying agent will issue in exchange for such lost, stolen or destroyed stock certificates, upon the making of an affidavit of that fact by the person claiming such stock certificate is lost, stolen or destroyed, the Merger Consideration. Parent may, in its reasonable discretion and as a condition precedent to the payment of such Merger Consideration, require the owners of such lost, stolen or destroyed stock certificates to deliver a bond in a reasonable sum as Parent may reasonably direct as indemnity against any claim that may be made against Parent, Merger Sub, the Surviving Corporation or the paying agent with respect to the stock certificates alleged to have been lost, stolen or destroyed.

Withholding Rights

U.S. Silica, Parent, Merger Sub, the Surviving Corporation and the paying agent will be entitled to deduct and withhold from any amounts otherwise payable pursuant to the Merger Agreement any amounts required to be deducted and withheld with respect to the making of such payment under the Code or other applicable law.

Completion of the Transaction; Closing

The closing of the Merger will take place (i) at 8:00 a.m. Eastern Time, on the third business day after the satisfaction or waiver of all of the conditions to closing (other than those conditions that by their terms are to be satisfied at the closing, but subject to the fulfillment or waiver of those conditions at the closing) or (ii) at such other place, such other time or on such other date as Parent and U.S. Silica may mutually agree in writing. If the Marketing Period (as defined in “—Financing Cooperation” on page 108 of this proxy statement) has not ended at the time of the satisfaction or waiver of the conditions to closing (other than those conditions that by their nature are to be satisfied at the closing of the Merger), then the closing of the Merger will instead take place on the earlier of (a) a business day during the Marketing Period specified by Parent on no less than three business days’ prior written notice to U.S. Silica and (b) the third business day after the final day of the Marketing Period (subject, in the case of each of clause (a) and (b), to the satisfaction or waiver of all of the conditions to closing (other than those conditions that by their nature are to be satisfied at the closing, but subject to the fulfillment or waiver of those conditions at the closing). On the closing date, Merger Sub and U.S. Silica will cause a certificate of merger to be executed and filed with the Secretary of State of the State of Delaware in accordance with the relevant provisions of the DGCL and will make all other filings required under the DGCL. The Merger will become effective at the time the certificate of merger is duly filed with the Secretary of State of the State of Delaware, or such later date and time as is agreed upon by the parties and specified in the certificate of merger (such date and time at which the Merger becomes effective is referred to as the “Effective Time”).

Dissenting Shares

Any Dissenting Shares shall not be converted into the right to receive the Merger Consideration. At the Effective Time, all Dissenting Shares shall be cancelled and cease to exist, and the holders of Dissenting Shares shall only be entitled to the rights granted to them under the DGCL. If any such holder fails to perfect or otherwise waives, withdraws or loses the right to appraisal under Section 262 of the DGCL or other applicable law, then the right of such holder to be paid the fair value of such Dissenting Shares shall cease and such Dissenting Shares shall be deemed to have been converted, as of the Effective Time, into and shall be exchangeable solely for the right to receive the Merger Consideration, without interest and subject to any applicable withholding of taxes.

90

Representations and Warranties

In the Merger Agreement, U.S. Silica has made customary representations and warranties to Parent and Merger Sub that are subject, in some cases, to specified exceptions and qualifications contained in the Merger Agreement or in the confidential disclosure schedules to the Merger Agreement. These representations and warranties relate to, among other things:

91

Many of the representations and warranties of U.S. Silica in the Merger Agreement are qualified by the knowledge of certain specified officers and members of senior management or a “materiality” or “material adverse effect” standard (that is, they will not be deemed to be untrue or incorrect unless their failure to be true or correct, individually or in the aggregate, would, as the case may be, be material or have a Company Material Adverse Effect).

For purposes of the Merger Agreement, a “Company Material Adverse Effect” means any change, effect, event, development, state of facts, circumstance, condition or occurrence that, individually or in the aggregate, (a) would or would reasonably be expected to prevent or materially delay the consummation by U.S. Silica of the Merger or the transactions contemplated by the Merger Agreement or (b) has or would reasonably be expected to have a material adverse effect on the business, results of operations, liabilities, assets or condition (financial or otherwise) of U.S. Silica or its subsidiaries, taken as a whole; provided, however that none of the following will be deemed, either alone or in combination, to constitute, and none of the following will be taken into account in determining whether there has been or would reasonably be expected to be, a Company Material Adverse Effect:

(i) the execution or delivery of the Merger Agreement, or the announcement of the transactions contemplated by the Merger Agreement (including the identity of Parent or Merger Sub or any affiliate thereof) (including the impact thereof on the relationship of U.S. Silica or any of its subsidiaries with employees, labor unions, financing sources, customers, suppliers, partners or other business relationships), or the compliance with or performance of the obligations under the Merger Agreement (provided that this clause (i) does not apply to (x) U.S. Silica’s and its subsidiaries’ compliance with or performance of the obligations described in “—Conduct of Business Prior to Closing” on page 94 of this proxy statement or (y) any representation or warranty to the extent the purpose of such representation or warranty is to address the consequences resulting from the announcement, execution, delivery or performance of or compliance with the Merger Agreement, or the Merger and the other transactions contemplated by the Merger Agreement or to the condition for Parent and Merger Sub to effect the Merger contained in the first bullet of “—Conditions to Closing of the Transaction—Conditions to Obligations of Parent and Merger Sub” on page 113 of this proxy statement);

(ii) changes or developments in the general market or economic conditions generally affecting the industries in which U.S. Silica or any of its subsidiaries participate (including the oil and gas industry or the industrial minerals industry), the economy as a whole or the credit, securities, financial, commodities or capital markets in general or the markets in which U.S. Silica and its subsidiaries operate;

(iii) any change after April 26, 2024 in applicable laws or any official interpretation thereof;

(iv) any change after April 26, 2024 in GAAP;

(v) any geopolitical conditions, the commencement, continuation or escalation of a war, material armed hostilities or other material international or national calamity or act of terrorism, rebellion or insurrection and acts of espionage;

(vi) volcanoes, tsunamis, pandemics or disease outbreaks, earthquakes, hurricanes, tornados or other natural disasters (or escalation or worsening of any such events or occurrences or, in the case of pandemics or disease outbreaks, any laws, legally binding pronouncements or legally binding guidelines promulgated by any governmental entity in response thereto);

(vii) any proceeding brought or threatened by U.S. Silica Stockholders arising out of the Merger Agreement or the transactions contemplated by the Merger Agreement asserting allegations of breach of fiduciary duty or violations of securities laws;

(viii) any labor strike, slow down, lockage or stoppage, pending or threatened, by a group of employees of U.S. Silica or any of its subsidiaries and of other companies that is organized by a labor union, works council or other labor organization;

(ix) any failure by U.S. Silica to meet any internal or public projections, forecasts, guidance, estimates, milestones, budgets or internal or published financial or operating predictions of revenue, earnings, cash

92

flow or cash position (it being understood that the facts or occurrences giving rise or contributing to such failure that are not otherwise excluded pursuant to another clause of this definition may be taken into account); or

(x) any decline in the trading price or trading volume of the Shares or any change in the ratings or ratings outlook for U.S. Silica or any of its subsidiaries or any of its securities (it being understood that the facts or occurrences giving rise or contributing to such decline or change that are not otherwise excluded pursuant to another clause of this definition may be taken into account).

Any change, effect, event, development, state of facts, circumstance, condition or occurrence referred to in the foregoing clauses (ii), (iii), (iv), (v), (vi) or (viii) may be taken into account in determining whether there has been, or would reasonably be expected to be, a Company Material Adverse Effect to the extent such change has a disproportionately adverse effect on U.S. Silica and its subsidiaries, taken as a whole, as compared to other participants in the industries in which U.S. Silica and its subsidiaries operate, in which case only the incremental disproportionate adverse effect shall be taken into account for the purpose of determining whether there has been, or would reasonably be expected to be, a Company Material Adverse Effect.

In the Merger Agreement, Parent and Merger Sub have made customary representations and warranties to U.S. Silica that are subject, in some cases, to specified exceptions and qualifications contained in the Merger Agreement. These representations and warranties relate to, among other things:

93

Many of the representations and warranties of Parent and Merger Sub in the Merger Agreement are qualified by the knowledge of the officers and directors of Parent and Merger Sub or a “materiality” or “material adverse effect” standard (that is, they will not be deemed to be untrue or incorrect unless their failure to be true or correct, individually or in the aggregate, would, as the case may be, be material or have a Parent Material Adverse Effect).

For purposes of the Merger Agreement, a “Parent Material Adverse Effect” means any change, effect, event, development, state of facts, circumstance, condition or occurrence that would have a material adverse effect on Parent’s or Merger Sub’s ability to timely consummate the Merger.

None of the representations and warranties in the Merger Agreement will survive the completion of the Merger.

Conduct of Business Prior to Closing

Certain covenants in the Merger Agreement restrict the conduct of U.S. Silica’s and its subsidiaries’ business between the date of the Merger Agreement and the Effective Time. Except (i) as expressly contemplated or required by the Merger Agreement; (ii) as required by applicable law; (iii) with the prior written consent of Parent (not to be unreasonably withheld, conditioned or delayed); or (iv) as set forth on the confidential disclosure schedules to the Merger Agreement, (x) U.S. Silica shall, and shall cause its subsidiaries to, use reasonable best efforts to (I) conduct its operations in the ordinary course of business consistent with past practice and (II) (A) preserve the goodwill of U.S. Silica and its subsidiaries and keep intact their respective material assets, properties and contracts, (B) keep available the services of its current officers and key employees, and (C) preserve the current relationships with key customers, suppliers, distributors, lessors, licensors, licensees, creditors, contractors, partners, service providers (including transload and transportation providers), governmental entities and other persons with whom U.S. Silica and its subsidiaries have significant business relationships and (y) U.S. Silica shall not, and shall cause its subsidiaries not to:

94

95

96

Access to Information

From April 26, 2024 to the earlier of the Effective Time and the termination of the Merger Agreement in accordance with its terms, U.S. Silica has agreed to (x) provide Parent and Merger Sub and their respective representatives with reasonable access, during normal business hours and upon reasonable advance notice, to U.S. Silica’s offices, properties, facilities, assets, books and records and officers, employees and other personnel and (y) (1) provide Parent and Merger Sub and their respective representatives with such financial, accounting, organizational and tax information as is reasonably available to U.S. Silica regarding possible alternative or supplemental structures (including internal restructurings and distributions by U.S. Silica or its subsidiaries) that may be desirable to Parent in connection with the Merger or regarding the tax consequences of the Merger and (2) reasonably consider Parent’s written proposals of such possible alternative or supplemental structures (including internal restructurings and distributions by U.S. Silica or its subsidiaries) in good faith, provided that such structures do not impede or delay the closing of the Merger or change the Merger Consideration, in each case, as Parent may reasonably request; provided, further, that (i) such access and disclosure will not unreasonably interfere with the normal operations and conduct of the business of U.S. Silica and its subsidiaries and will be coordinated through a transition committee to be formed by the parties for the purpose of discussing, planning and preparing to implement (following the Effective Time) transition, integration and related matters and (ii) neither U.S. Silica nor its subsidiaries will be required to provide access to, or to disclose any information to Parent, Merger Sub or their respective representatives if such access or disclosure would, in the reasonable good faith judgment of U.S. Silica’s legal counsel, (A) waive any attorney-client privilege, work-product doctrine or other similar legal privilege or (B) be in violation of applicable law, or (C) contravene the provisions of any contract to which U.S. Silica or any of its subsidiaries is a party as of April 26, 2024.

U.S. Silica has also agreed to provide Parent and its representatives with (1) monthly and quarterly management reports to the extent prepared in the ordinary course of business, (2) quarterly business reviews to the extent prepared in the ordinary course of business, and (3) strategic planning studies and capital investment project documents to the extent prepared in the ordinary course of business.

The “Go Shop” Period—Solicitation by U.S. Silica

During the period beginning on April 26, 2024 and continuing until the No-Shop Period Start Date, U.S. Silica and its representatives have the right to:

97

As promptly as reasonably practicable, and in any event within one business day following the No-Shop Period Start Date, U.S. Silica will deliver to Parent a written notice setting forth the identity of each person or group of persons from whom U.S. Silica or any of its representatives has received an Acquisition Proposal, in each case, prior to the No-Shop Period Start Date.

As used in this proxy statement:

98

The “No Shop” Period—No Solicitation by U.S. Silica

Except as expressly permitted by the Merger Agreement, from the No-Shop Period Start Date until the earlier of the termination of the Merger Agreement in accordance with its terms and the closing date of the Merger, U.S. Silica will not, and will cause its representatives not to, directly or indirectly:

Notwithstanding the foregoing, if prior to the receipt of the Stockholder Approval, (i) U.S. Silica receives a bona fide Acquisition Proposal from any person that did not result, directly or indirectly, from a breach of the non-solicitation restrictions in the Merger Agreement and (ii) the Board of Directors determines in good faith (after consultation with its independent financial advisor and outside legal counsel) that such Acquisition Proposal either constitutes a Superior Proposal (as defined below), or would reasonably be expected to result in a Superior Proposal, and the failure to take such actions in clauses (x) and (y) below would be inconsistent with its fiduciary duties under applicable law, then U.S. Silica may, directly or indirectly, in response to such Acquisition Proposal, (x) enter into an Acceptable Confidentiality Agreement with such person that has made or delivered such Acquisition Proposal and (y) pursuant thereto, participate or engage in discussions or negotiations with, furnish any non-public information or data relating to U.S. Silica or its subsidiaries to, or afford access to the business, properties, assets, books, records or other non-public information or data, or to any personnel of U.S. Silica or its subsidiaries to such person or its representatives. U.S. Silica must promptly (and in any event within 24 hours) provide to Parent and its representatives, or provide Parent and its representatives access to, any non-public information that is provided to any third party or its representatives if such information was not previously made available to Parent, Merger Sub or their representatives.

Subject to certain limited exceptions, during the period commencing on the date of the Merger Agreement and continuing until the earlier of the consummation of the closing or the valid termination of the Merger Agreement, neither the Board nor any committee thereof will take the following actions (each, a “Board Recommendation Change”):

99

During the period commencing on the date of the Merger Agreement and continuing until the earlier of the consummation of the closing or the valid termination of the Merger Agreement, neither the Board nor any committee thereof will cause or permit U.S. Silica or any of its subsidiaries to enter into any letter of intent, agreement in principle, memorandum of understanding, merger agreement, acquisition agreement or other contract relating to an Acquisition Proposal, other than an Acceptable Confidentiality Agreement entered into in accordance with the Merger Agreement (any of the foregoing, an “Alternative Acquisition Agreement”), or publicly propose or agree to do any of the foregoing.

Prior to obtaining the Stockholder Approval, if U.S. Silica receives a bona fide written Acquisition Proposal from any person that did not result, directly or indirectly, from a breach of the non-solicitation restrictions in the Merger Agreement, that the Board determines in good faith (after consultation with its independent financial advisor and outside legal counsel) constitutes a Superior Proposal (it being understood that any such conclusion in and of itself shall not be deemed a Board Recommendation Change), then the Board may effect a Board Recommendation Change with respect to such Superior Proposal or authorize U.S. Silica to terminate the Merger Agreement pursuant to the terms thereof to enter into an Alternative Acquisition Agreement with respect to such Superior Proposal. U.S. Silica, however, is not entitled to effect a Board Recommendation Change or terminate the Merger Agreement unless U.S. Silica has provided to Parent at least five business days’ prior written notice of U.S. Silica’s intention to take such action, which notice will specify the identity of the person or “group” of persons making such Acquisition Proposal, the material terms and conditions thereof and include copies of all relevant documents related to such Acquisition Proposal, and unless:

In the event of any material modifications to such Acquisition Proposal, U.S. Silica is required to deliver a new written notice to Parent describing such modifications and to again comply with the negotiation obligations described above for an additional three business days following such new notice.

100

The Board may, at any time prior to the receipt of the Stockholder Approval, effect a Board Recommendation Change in response to an Intervening Event (as defined below) if the Board determines in good faith (after consultation with its independent financial advisor and outside legal counsel) that the failure to do so would be inconsistent with its fiduciary duties pursuant to applicable law (it being understood that any such determination in and of itself will not be deemed a Board Recommendation Change). U.S. Silica will be entitled to effect a Board Recommendation Change in response to an Intervening Event pursuant to the Merger Agreement if and only if:

In the event of any material modification to the Intervening Event occurs, U.S. Silica is required to deliver a new written notice to Parent describing such modification and to again comply with the negotiation obligations described above and the time period set forth above shall recommence and be extended for three business days from the day of such new notice.

Nothing in the Merger Agreement limits U.S. Silica’s or the Board’s ability to (i) take and disclose to U.S. Silica Stockholders a position contemplated by Rule 14e-2(a) promulgated under the Exchange Act, or complying with Rule 14d-9 promulgated under the Exchange Act, including a “stop, look and listen” communication by the Board to the U.S. Silica Stockholders pursuant to Rule 14d-9(f) promulgated under the Exchange Act; (ii) comply with Item 1012(a) of Regulation M-A promulgated under the Exchange Act; or (iii) make any disclosure to U.S. Silica Stockholders required by applicable law, regulation or stock exchange rule or listing agreement, it being understood that (A) any such statement or disclosure made by the Board must comply with the terms and conditions of the Merger Agreement and not limit or otherwise affect the obligations of U.S. Silica, its subsidiaries or its Board of Directors or the rights of Parent under the non-solicitation provisions of the Merger Agreement, and (B) U.S. Silica will not be permitted to effect a Board Recommendation Change other than in accordance with the terms and conditions of the Merger Agreement.

As used in this proxy statement:

101

U.S. Silica Stockholder Meeting; Proxy Statement

As promptly as practicable, U.S. Silica will cause this proxy statement to be mailed to U.S. Silica Stockholders as of the Record Date. U.S. Silica will, in accordance with applicable law and the rules of the NYSE, establish the Record Date, duly call, give notice of, convene and hold a meeting of U.S. Silica Stockholders as promptly as reasonably practicable after the date of the Merger Agreement for the purpose of voting on the approval and adoption of the Merger Agreement.

U.S. Silica has agreed to include in this proxy statement (x) the Board’s recommendation that U.S. Silica Stockholders vote in favor of the Merger Proposal and (y) the written opinion of Piper Sandler, dated as of the date of the Merger Agreement, that, as of such date, the Merger Consideration is fair, from a financial point of view, to the U.S. Silica Stockholders. U.S. Silica has further agreed to use its reasonable best efforts to solicit proxies in favor of the approval and adoption of the Merger Agreement and to not adjourn the stockholder meeting other than (i) with the consent of Parent; (ii) if a quorum has not been established; (iii) after consultation with Parent, to allow reasonable additional time for the filing and mailing of any supplemental or amended disclosure which the Board has determined in good faith is necessary or advisable and for such supplemental or amended disclosure to be disseminated and reviewed by U.S. Silica Stockholders prior to the meeting; or (iv) to allow reasonable additional time to solicit additional proxies if necessary in order to obtain the Stockholder Approval.

Consents, Approvals and Filings

U.S. Silica, Parent and Merger Sub have each agreed to use their reasonable best efforts to take, or cause to be taken, all actions that are necessary, proper or advisable to cause the conditions to the Merger to be satisfied and to complete the Merger and the other transactions contemplated by the Merger Agreement as promptly as practicable, including making appropriate filings under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (the “HSR Act”) and making any filings required under the Communications Act of 1934. Each of the parties to the Merger Agreement must use reasonable best efforts to supply any additional information and documentary material that may be reasonably requested pursuant to the foregoing. Subject to applicable law relating to the exchange of information, U.S. Silica and Parent have each agreed to use its reasonable best efforts to:

102

Notwithstanding the forgoing, Parent has the right under the Merger Agreement, subject to requirements to (i) give prior notice to, and consult with, U.S. Silica, and (ii) take U.S. Silica’s views into account in good faith, to control and lead all communications and strategy relating to any process under the HSR Act and any antitrust law.

Parent agreed to use its reasonable best efforts to promptly (and in any event, prior to the Outside Date (as defined in “—Termination of the Merger Agreement”)) resolve such objections, if any, as may be asserted by any governmental entity with respect to the Merger or the other transactions contemplated by the Merger Agreement under the HSR Act or any antitrust law. Parent further agreed, to the extent necessary to obtain any waiver, permit, approval, clearance or consent from any governmental entity under the HSR Act or antitrust law or which is otherwise required to satisfy the Absence of Closing Legal Impediments Condition or the Regulatory Approvals Condition, as applicable, or to avoid the entry of or have lifted, vacated, reversed or terminated any Closing Legal Impediment, in each case, prior to the Outside Date, to promptly take, or cause its subsidiaries to take, the following actions:

provided, however, that Parent, Merger Sub, U.S. Silica and their respective subsidiaries are not obligated to take any of the foregoing actions to the extent such actions would have, or would reasonably be expected to have, individually or in the aggregate, a material adverse effect on the business, operations or financial condition of U.S. Silica.

Employee Benefits Matters

The Merger Agreement provides that, except as otherwise required by a collective bargaining agreement, agreement with any works council or similar labor contract (each, a “Labor Agreement”), during the period commencing at the closing of the Merger and ending on the 12-month anniversary thereof, each Continuing Employee will receive, for so long as such Continuing Employee remains employed by Parent or any of its subsidiaries (including the Surviving Corporation), during such period: (i) an annual base salary or wage rate and target short-term incentive compensation opportunity (including bonus and commission) that, in each case, is not less favorable than was provided to such Continuing Employee immediately prior to the Effective Time; (ii) for each Continuing Employee who (A) participated in U.S. Silica’s annual equity incentive program prior to the Effective Time, and (B) is not invited to participate in the management equity incentive program maintained by Parent or its affiliate following the closing of the Merger, a target cash-based incentive compensation opportunity

103

that is substantially equivalent to the target annual equity award opportunity provided to such Continuing Employee prior to the closing of the Merger and (iii) all other compensation and employee benefits (excluding any equity-based or other long-term incentive, retention, change in control or similar one-time or special benefits or arrangements, non-qualified deferred compensation, postretirement health and welfare benefits and defined benefit pension benefits) that are substantially comparable in the aggregate to those provided to the Continuing Employee immediately before the Effective Time. Continuing Employees covered by a Labor Agreement will continue to be paid compensation, benefits and, if applicable, severance in accordance with the terms of the applicable Labor Agreement. In addition, each Continuing Employee whose employment is involuntarily terminated without cause by U.S. Silica during the one-year period following the Effective Time will receive severance benefits no less favorable than the severance benefits that would have been provided to the Continuing Employee under U.S. Silica’s severance arrangements in effect immediately prior to the Effective Time.

The Merger Agreement also provides that, with respect to benefit plans maintained by Parent or any of its subsidiaries, including the Surviving Corporation (including any vacation, paid time-off and severance plans, but excluding any plan providing for qualified or non-qualified defined benefit pension benefits, non-qualified deferred compensation, or post-termination or retiree health or welfare benefits), for all purposes, including determining eligibility to participate, level of benefits, vesting and benefit accruals, each Continuing Employee’s service with U.S. Silica or any of its subsidiaries (and any predecessor thereto), as reflected in U.S. Silica’s records, shall be treated as service with Parent or any of its subsidiaries, including the Surviving Corporation; provided, that such service need not be recognized to the extent that such recognition would result in any duplication of benefits.

The Merger Agreement also provides that Parent will, or will cause its subsidiaries to, use commercially reasonable efforts to (i) waive or cause to be waived any pre-existing condition limitations, exclusions, evidence of insurability, actively-at work requirements and waiting periods under any welfare benefit plan maintained by Parent or any of its subsidiaries in which Continuing Employees (and their eligible dependents) will be eligible to participate from and after the Effective Time, except to the extent that such pre-existing condition limitations, exclusions, actively-at work requirements and waiting periods would not have been satisfied or waived under the comparable U.S. Silica plan immediately prior to the Effective Time and (ii) recognize, or cause to be recognized, the dollar amount of all co-payments, deductibles and similar expenses incurred by each Continuing Employee (and his or her eligible dependents) during the calendar year in which the Effective Time occurs for purposes of satisfying such year’s deductible and co-payment limitations under the relevant welfare benefit plans in which such Continuing Employee (and his or her eligible dependents) will be eligible to participate from and after the Effective Time.

Directors’ and Officers’ Indemnification and Insurance

After the Effective Time, Parent will, and will cause the Surviving Corporation to, indemnify, defend and hold harmless, and advance expenses as incurred by, to the fullest extent permitted under applicable law, the certificate of incorporation, bylaws or similar organizational documents of U.S. Silica and any contract of U.S. Silica and its subsidiaries with any of their respective directors or officers that provide for the indemnification or advancement of expenses to such persons in existence as of the date of the Merger Agreement (each, an “Indemnification Contract”), each present and former director and officer of U.S. Silica or any of its subsidiaries (including any such person who served as a director, officer, member, trustee, employee, agent or fiduciary of another corporation, partnership, joint venture, trust, pension or other employee benefit plan or enterprise at the request of or for the benefit of U.S. Silica or any of its subsidiaries (including as a fiduciary of a U.S. Silica benefit plan) (when acting in such capacity, each an “Indemnitee”), against any costs or expenses (including reasonable attorneys’ fees), judgments, settlements, fines, losses, claims, damages or liabilities incurred in connection with any proceeding or investigation, whether civil or criminal, administrative or investigative, whenever asserted, arising out of or pertaining to any matter existing or occurring at or prior to the Effective Time, including in connection with the Merger Agreement or the transactions contemplated by the Merger Agreement and actions to enforce any indemnification or advancement right of any Indemnitee.

104

Under the Merger Agreement, Parent has agreed that all rights to exculpation, indemnification and advancement of expenses arising from, relating to or otherwise in respect of acts or omissions occurring prior to the Effective Time existing as of the Effective Time (including in connection with the Merger Agreement or the transactions contemplated thereby) in favor of the Indemnitees (as provided in U.S. Silica’s and its subsidiaries’ certificate of incorporation or bylaws or similar organizational documents) shall survive the Merger and shall continue in full force and effect in accordance with their terms. For a period of no less than six years from the Effective Time, Parent will cause the Surviving Corporation to maintain in effect the exculpation, indemnification and advancement of expenses provisions in favor of an Indemnitee as provided in (i) the applicable organizational documents in effect as of the date of the Merger Agreement and (ii) any Indemnification Contract, and will not amend, repeal or otherwise modify any such provisions in any manner that would adversely affect the rights thereunder of Indemnitees; provided, however, that all rights to exculpation, indemnification and advancement of expenses in respect of any proceeding pending or asserted, investigation or any claim made within such period shall continue until the final disposition of such proceeding or investigation.

The Merger Agreement provides that, subject to certain limits on the premium to be paid, from and for six years after the Effective Time, Parent and the Surviving Corporation will be jointly and severally responsible for maintaining for the benefit of the directors and officers of U.S. Silica and its subsidiaries, as of the date of the Merger Agreement and as of the closing date of the Merger, an insurance and indemnification policy that provides coverage for events occurring at or prior to the Effective Time, that is substantially equivalent to and in any event not less favorable in the aggregate than the existing policy of U.S. Silica and its subsidiaries. In the event that either Parent or the Surviving Corporation or any of its successors or assigns (i) consolidates with or merges into any other person and is not the continuing or Surviving Corporation or entity of such consolidation or merger or (ii) transfers or conveys all or substantially all of its properties and assets to any person, then, and in each case, Parent will, and the Surviving Corporation will, cause proper provision to be made so that the successor or assign will expressly assume the obligations described above.

Takeover Statutes

The parties to the Merger Agreement have agreed to take all action necessary so that no state takeover law or state law that purports to limit or restrict business combinations or the ability to acquire or vote Shares (including any “control share acquisition,” “fair price,” “business combination” or other similar takeover law) is or becomes applicable to restrict or prohibit the transactions contemplated by the Merger Agreement. If any such law becomes or is deemed to be applicable to U.S. Silica, Parent or Merger Sub, the Merger or any other transaction contemplated by the Merger Agreement, then U.S. Silica will take all action necessary to eliminate the effects of such law so that such transactions may be consummated as promptly as practicable on the terms of the Merger Agreement.

Section 16 Matters

Prior to the Effective Time, U.S. Silica and Parent will take all such steps as may be reasonably necessary to cause any dispositions of Shares (including derivative securities with respect to Shares) resulting from the transactions contemplated by the Merger Agreement by each individual who is subject to the reporting requirements of Section 16(a) of the Exchange Act with respect to U.S. Silica, to be exempt under Rule 16b-3 promulgated under the Exchange Act.

Stockholder Litigation

U.S. Silica will give Parent a reasonable opportunity to participate in the defense or settlement of any stockholder litigation against U.S. Silica and/or its directors and officers relating to the Merger Agreement or the transactions contemplated by the Merger Agreement, including the Merger. U.S. Silica will promptly notify Parent of any such litigation that is brought or, to the knowledge of U.S. Silica, threatened in writing and will keep Parent reasonably and promptly informed of the status thereof. U.S. Silica will not settle any such

105

stockholder litigation or related proceeding without the prior written consent of Parent (not to be unreasonably withheld, conditioned or delayed).

NYSE Delisting

The Surviving Corporation will cause U.S. Silica’s securities to be de-listed from the NYSE and de-registered under the Exchange Act as promptly as practicable following the Effective Time, and prior to the Effective Time U.S. Silica will reasonably cooperate with Parent with respect thereto.

U.S. Silica Indebtedness

U.S. Silica will use reasonable best efforts to have delivered to Parent at least two business days prior to the closing date of the transactions, an appropriate and customary payoff letter (the “Payoff Letter”) with respect to U.S. Silica’s existing credit facility, specifying the aggregate payoff amount of U.S. Silica’s obligations thereunder and providing for a release of all liens and guarantees thereunder upon the receipt of the respective payoff amounts specified in the Payoff Letter, and all customary documentation relating to the release of all liens with respect to U.S. Silica’s existing credit facility. Parent and Merger Sub will be responsible for paying all amounts under the Payoff Letter.

Financing Efforts

Parent has agreed to use its reasonable best efforts to take and to cause each of its subsidiaries to use their respective reasonable best efforts to take, or cause to be taken, all actions, and do, or cause to be done, all things necessary, proper or advisable to obtain the proceeds of the Financing (taking into account the amount of any applicable alternative financing to separately finance the oil and gas proppants business (the “Alternative Financing”)) in an amount sufficient for the satisfaction of all of Parent’s and Merger Sub’s obligations in connection with the closing of the Merger under the Merger Agreement and under the Commitment Letters (the “Financing Amounts”) on the date on which the Merger is required to be consummated pursuant to the terms of the Merger Agreement, including by using reasonable best efforts to:

In the event that all conditions contained in the Commitment Letters or the Definitive Agreements (other than the consummation of the Merger, those conditions that by their nature are to be satisfied at the closing of the Merger and those conditions the failure of which to be satisfied is attributable to a breach by Parent or Merger Sub of its representations, warranties, covenants or agreements contained in the Merger Agreement, and other than, with respect to the Debt Financing, the availability of the Equity Financing and, with respect to the Equity Financing, the availability of the Debt Financing) have been satisfied, Parent and Merger Sub have agreed to fully enforce the counterparties’ obligations under the Commitment Letters and cause the Guarantors to, and to use reasonable best efforts to cause the Debt Financing Entities to, comply with their respective obligations thereunder, including to fund the Financing.

106

Parent and Merger Sub have agreed that they will not, and they will not permit any of their subsidiaries to, without the prior written consent of U.S. Silica, (i) terminate or cause the termination of any Commitment Letter or any Definitive Agreement, or (ii) permit, consent to or agree to any amendment, replacement, supplement, or modification to, or any waiver of, any provision or remedy under, any Commitment Letter or any Definitive Agreement if such amendment, replacement, supplement, modification, waiver or remedy:

provided that the Debt Commitment Letter may be amended to add additional lenders, lead arrangers, bookrunners, syndication agents or other entities who had not executed the Debt Commitment Letter as of April 26, 2024, so long as any such addition would not effect a Prohibited Modification.

Parent has further agreed to promptly deliver to U.S. Silica copies of any amendment, replacement, supplement, termination, modification or waiver to the Commitment Letters and/or Definitive Agreements.

In the event that any portion of the Debt Financing required to pay the Financing Amounts becomes unavailable, regardless of the reason therefor, Parent has agreed to (i) promptly notify U.S. Silica in writing of such unavailability and the reason therefor and (ii) use reasonable best efforts, and cause each of its subsidiaries to use their respective reasonable best efforts, to arrange and obtain, as promptly as practicable following the occurrence of such event, alternative financing for any such unavailable portion from the same or alternative sources (the “Replacement Financing”) in an amount sufficient, when taken together with the available portion of the Financing, to pay the Financing Amounts, and which does not include any Prohibited Modifications.

Parent will provide U.S. Silica with prompt written notice (i) of any actual breach, default, cancellation, termination or repudiation by any party to the Commitment Letters or any Definitive Agreement of which Parent becomes aware and (ii) upon receipt of any written notice or other written communication from any Debt Financing Entity or Guarantor or other financing source with respect to any actual or threatened breach, default, cancellation, termination or repudiation by any party to the Commitment Letters or any Definitive Agreement of any provision thereof. Parent will further keep U.S. Silica informed on a reasonably current basis of the status of its efforts to consummate the Financing, including any Replacement Financing. Parent is not required to pay any fees or any interest rates applicable to the Debt Financing in excess of those contemplated by the Debt Commitment Letter (after giving effect to the “market flex” provisions), or agree to terms materially less favorable to Parent or U.S. Silica than the terms contained in or contemplated by the Debt Commitment Letter (in either case, whether to secure waiver of any conditions contained therein or otherwise). Compliance by Parent with the provisions of the Merger Agreement described in this section will not relieve Parent of its obligations to consummate the transactions contemplated by the Merger Agreement whether or not the Financing, any Replacement Financing or any Alternative Financing is available.

After providing written notice to U.S. Silica in accordance with the definition of Alternative Financing Event (as defined below), Parent may seek to obtain Alternative Financing in lieu of a portion of the Debt Financing contemplated by the Debt Commitment Letter. Such Alternative Financing will not, without the prior

107

consent of U.S. Silica, (i) include any Prohibited Modifications or (ii) require U.S. Silica to provide any type of cooperation to Parent and such sources of Alternative Financing beyond the type of cooperation required in respect of the Debt Financing contemplated by the Debt Commitment Letter. Parent will use reasonable best efforts, and cause each of its subsidiaries to use their respective reasonable best efforts to limit additional information and document requests made by the sources of such Alternative Financing to such information and document requests of the type made by (or on behalf of) the Debt Financing Entities in respect of the Debt Commitment Letter. In no event will the satisfaction of any cooperation covenants with respect to the Alternative Financing by U.S. Silica, its subsidiaries or any of their respective affiliates be a condition to any of Parent’s or Merger Sub’s obligations under the Merger Agreement to the extent (x) such Alternative Financing does not arise pursuant to an Alternative Financing Event or (y) any requests in connection therewith are not requested by Parent in writing at least three business days prior to the closing of the Merger. As used in this proxy statement, an “Alternative Financing Event” will be deemed to have occurred once Parent notifies U.S. Silica in writing that it intends to obtain Alternative Financing (including the reasonably detailed terms and provisions thereof) prior to the date that is sixty days after April 26, 2024.

To the extent Parent obtains Replacement Financing or Alternative Financing (solely to the extent such Alternative Financing arises pursuant to an Alternative Financing Event) or amends, replaces, supplements, modifies or waives any of the Commitment Letters or the Definitive Agreements, in each case pursuant to the provisions described in this section, the aforementioned provisions will apply to such Replacement Financing, such Alternative Financing, the financing sources and/or their related parties in respect thereof, the commitments thereunder and the agreements with respect thereto, or the Financing, as applicable, as so amended, replaced, supplemented, modified or waived. Parent will use reasonable efforts to coordinate the requests for information or meetings or other items requiring U.S. Silica’s cooperation under the Merger Agreement as among all Debt Financing Entities, including with respect to any Replacement Financing or Alternative Financing.

Financing Cooperation

U.S. Silica has agreed to use its reasonable best efforts, and to use its reasonable best efforts to cause its subsidiaries to use their respective reasonable best efforts, and to use its reasonable best efforts to cause their respective representatives to use their reasonable best efforts, to provide customary cooperation in connection with the arrangement and implementation of the Debt Financing, to the extent reasonably requested by Parent in writing, including using reasonable best efforts to:

108

The foregoing notwithstanding, none of U.S. Silica nor any of its subsidiaries or their respective representatives will be required to take or permit the taking of any action pursuant to this section that could:

109

Nothing contained in the Merger Agreement will require U.S. Silica or any of its subsidiaries, prior to the closing of the Merger, to be an issuer or other obligor with respect to the Debt Financing. Parent has agreed to, promptly upon written request by U.S. Silica, reimburse U.S. Silica or any of its subsidiaries for all reasonable and documented out-of-pocket costs incurred by them or their respective representatives in connection with such cooperation and to reimburse, indemnify and hold harmless U.S. Silica and its subsidiaries and their respective representatives from and against any and all liabilities and losses suffered or incurred by them in connection with the arrangement of the Debt Financing or the transactions contemplated in connection therewith, any action taken by them at the request of Parent or its representatives thereby and any information used in connection therewith (other than liabilities or losses resulting solely from information provided by U.S. Silica or its subsidiaries), in each case, other than to the extent any of the foregoing was suffered or incurred as a result of the bad faith, gross negligence or willful misconduct of, or material breach of the Merger Agreement by, U.S. Silica, its subsidiaries or any of their representatives, as determined in a final and non-appealable judgment by a court of competent jurisdiction.

The parties have agreed that the financing cooperation provisions of the Merger Agreement represent the sole obligation of U.S. Silica, its subsidiaries and their respective representatives with respect to cooperation in connection with the arrangement of any financing (including the Financing and the Alternative Financing, as applicable) to be obtained by Parent or Merger Sub with respect to the transactions contemplated by the Merger Agreement and the Commitment Letters (or the commitment letter governing the Alternative Financing, as applicable), and no other provision of the Merger Agreement (including the exhibits and schedules thereto) or the Commitment Letters will operate to expand or modify such obligations.

U.S. Silica has further agreed to, and to cause its subsidiaries to, use reasonable best efforts to periodically update any Required Financial Information provided to Parent as may be necessary so that such Required Financial Information is (a) Compliant (as defined and further described in the Merger Agreement) and (b) meets the applicable requirements set forth in the definition of “Required Financial Information” in the Merger Agreement. Parent may, to most effectively access the financing markets, request the cooperation of U.S. Silica and its subsidiaries as described in this section of this proxy statement at any time, and from time to time and on multiple occasions, between April 26, 2024 and the closing of the Merger (provided that the Marketing Period

110

will not be applicable as to each attempt to access the markets (it being understood and agreed that once the Marketing Period has commenced and then been completed, there will not be a subsequent Marketing Period)). Parent has agreed to provide U.S. Silica drafts of all Offering Documents and all marketing materials for the Debt Financing (and the Alternative Financing, as applicable) with a reasonable time to review such documents and materials, and subject to Parent’s compliance with such obligation, U.S. Silica agrees to use reasonable best efforts to review all such Offering Documents and marketing materials and identify for Parent any information contained therein that it reasonably believes constitutes material non-public information with respect to U.S. Silica and its subsidiaries (taken as a whole) or their respective securities. If U.S. Silica identifies any such information, and such information is customarily included in offering documents or marketing materials for debt financing of the type consistent with the Debt Financing, is reasonably requested by Parent to be included in the Offering Documents or marketing materials for the Debt Financing and does not include information as to which U.S. Silica reasonably objects, U.S. Silica will file a Current Report on Form 8-K containing such material non-public information.

All non-public or otherwise confidential information regarding U.S. Silica or any of its affiliates obtained by Parent or its representatives pursuant to the provision of the Merger Agreement described in this section will be kept confidential in accordance with the Apollo Confidentiality Agreement. U.S. Silica has consented to the use of its and its subsidiaries’ logos in connection with the Debt Financing (and the Alternative Financing, as applicable) (provided that such trademarks and logos are used solely in a manner that is not intended to or reasonably likely to harm or disparage U.S. Silica or any of its subsidiaries or the reputation or goodwill of U.S. Silica or any of its subsidiaries).

The “Marketing Period” is defined as the first period of 15 consecutive days after the date of the Merger Agreement (a) throughout and at the end of which Parent will have the Required Financial Information and the Required Financial Information will be Compliant and (b) throughout and at the end of which the conditions for each of the parties to effect the Merger described in “—Conditions to Closing of the Transaction—Conditions to Each Party’s Obligations” on page 112 of this proxy statement and the conditions for Parent and Merger Sub to effect the Merger described in “—Conditions to Closing of the Transaction—Conditions to Obligations of Parent and Merger Sub” on page 113 of this proxy statement (other than those conditions that by their nature are to be satisfied at the closing of the Merger, but subject to the satisfaction or waiver of such conditions) have been satisfied or waived and nothing has occurred and no condition exists that would cause any of such conditions to fail to be satisfied assuming the closing of the Merger were to be scheduled for any time during such 15 consecutive day period; provided that (i) May 27, 2024, June 19, 2024, July 3, 2024, July 4, 2024, July 5, 2024, November 28, 2024, November 29, 2024 and January 20, 2025 do not constitute days for purposes of calculating such 15 consecutive day period (provided, however, that such exclusion will not restart such period) and (ii) if such 15 consecutive day period has not been completed on or prior to (x) August 16, 2024, such 15 consecutive day period will not commence until September 3, 2024 and (y) December 13, 2024, such 15 consecutive day period will not commence until January 6, 2025. Further, the Marketing Period will end on any earlier date prior to the expiration of the 15 consecutive day period described above if the Debt Financing is closed on such earlier date and the Marketing Period will not be deemed to have commenced if, after the date of the Merger Agreement and prior to the completion of such 15 consecutive day period:

111

If at any time U.S. Silica in good faith believes that it has provided the Required Financial Information, it may deliver to Parent a written notice to that effect (stating when it believes it completed such delivery), in which case, the requirement to deliver the Required Financial Information will be deemed to have been satisfied as of the date of delivery of such notice, unless Parent in good faith reasonably believes U.S. Silica has not completed the delivery of the Required Financial Information on such date and, within three business days after the date of delivery of such notice, delivers a written notice to U.S. Silica to that effect (stating with specificity which Required Financial Information U.S. Silica has not delivered). Following delivery of such Required Financial Information specified in such notice, the Marketing Period will commence so long as all other conditions and requirements for the Marketing Period to commence are satisfied (provided that such written notice from Parent to U.S. Silica will not prejudice U.S. Silica’s right to assert that the Required Financial Information was, in fact, delivered and is Compliant).

In no event shall (a) any circumstance with respect to Parent’s efforts with respect to any Alternative Financing in any way restart, delay or otherwise prolong the Marketing Period or (b) any circumstance with respect to Parent’s efforts to make an offering of debt securities in any way restart, delay, or otherwise prolong the Marketing Period unless Parent notifies U.S. Silica of its intent to make an offering of debt securities on or prior to the latest date all or a portion of the Debt Financing may “flex” into such debt securities pursuant the “flex” provisions of the applicable fee letter entered into in connection with the Debt Commitment Letter.

Conditions to Closing of the Transaction

Conditions to Each Party’s Obligations

The respective obligations of each party to consummate the Merger are subject to the satisfaction (or waiver, if permitted by law) of the following conditions at or prior to the Effective Time:

Conditions to Obligations of U.S. Silica

The obligations of U.S. Silica to effect the Merger is also subject to the fulfillment (or waiver by U.S. Silica) of the following conditions at or prior to the Effective Time:

112