VOTING AGREEMENT

Exhibit 10.1

VOTING AGREEMENT

     This Voting Agreement (this “ Agreement ”) is dated as of April 3, 2005, by and among Petrohawk Energy Corporation (“ Petrohawk Energy Corporation ” or “Petrohawk”), Mission Resources Corporation, a Delaware corporation (“ Mission ”) and Harbert Distressed Investment Master Fund, Ltd., an exempt company organized in the Cayman Islands (the “ Stockholder ”).

     WHEREAS, Stockholder desires that Petrohawk, Petrohawk Acquisition Corporation, a Delaware corporation and wholly-owned subsidiary of Petrohawk (“ Purchaser ”), and Mission, enter into the Agreement and Plan of Merger dated the date hereof (the “ Merger Agreement ”); undefined capitalized terms herein are defined in the Merger Agreement) providing for the merger of Mission with and into Purchaser (the “ Merger ”) upon the terms and subject to the conditions set forth in the Merger Agreement;

     WHEREAS, Stockholder is executing this Agreement as an inducement to Petrohawk to enter into and execute the Merger Agreement (and this Agreement shall not be effective until the parties to the Merger Agreement execute the Merger Agreement); and

     WHEREAS, the Board of Directors of Mission has adopted such resolutions as are necessary so that the provisions of Section 203 of the DGCL are inapplicable to the execution and performance of this Agreement;

     NOW, THEREFORE, in consideration of the execution and delivery by Petrohawk of the Merger Agreement and the mutual covenants, conditions and agreements contained herein and therein, the parties agree as follows:

     1.  Representations and Warranties.

     (a) Stockholder represents and warrants to Petrohawk as follows:

     (i) Stockholder is the record and beneficial owner of that number of shares of capital stock of Mission set forth opposite its name on Schedule A (together with any other shares of other capital stock of Mission acquired after the date hereof including through the exercise of any stock options, warrants or similar instruments) being collectively referred to herein as the “ Subject Shares ”) and the other securities exercisable or exchangeable for such capital stock listed on Schedule A (the “ Other Securities ” and, together with the Subject Shares, the “ Covered Securities ”). ¹ Stockholder has the sole right to vote and Transfer (as defined herein) the Covered Securities set forth opposite its name on Schedule A , and none of such Covered Securities is subject to any voting trust or other agreement, arrangement or restriction with respect to the voting or the Transfer of the Subject Shares, except (A) as provided by this Agreement (it being understood that any pledge of the Pledged Shares (as defined below) shall not be a breach of this representation) and (B) those arising under applicable securities laws. Stockholder has all requisite power and authority to enter into this Agreement and to perform its obligations hereunder. Stockholder is duly organized,

validly existing and in good standing under the laws of its jurisdiction of organization. The execution and delivery of this Agreement by Stockholder and the performance by Stockholder of its obligations hereunder have been duly authorized by all necessary action on the part of Stockholder. This Agreement has been duly executed and delivered by, and constitutes a valid and binding agreement of, Stockholder, enforceable against Stockholder in accordance with its terms, except as enforcement may be limited by or subject to the effects of bankruptcy, insolvency, reorganization, moratorium and other laws relating to or affecting the rights of creditors and of general principles of equity.

     (ii) Neither the execution and delivery of this Agreement nor the performance by Stockholder of its obligations hereunder will result in a violation of, or a default under, or conflict with, (A) any provision of its certificate of incorporation, bylaws, partnership agreement, limited liability company agreement or similar organizational documents, (B) any contract, trust, commitment, agreement, understanding, arrangement or restriction of any kind (other than as may relate to the Pledged Shares but subject to the proviso set forth in (iv) below) to which Stockholder is a party or bound or to which the Covered Securities are subject, except, in the case of clause (B), as would not prevent, delay or otherwise materially impair Stockholder’s ability to perform its obligations hereunder. Execution, delivery and performance of this Agreement by Stockholder will not violate, or require any consent, approval or notice under, any provision of any judgment, order, decree, statute, law, rule or regulation applicable to Stockholder or the Covered Securities, except (x) for any reports under Sections 13(d) of the Exchange Act as may be required in connection with this Agreement and the transactions contemplated hereby or (y) as would not reasonably be expected to prevent, delay or otherwise materially impair Stockholder’s ability to perform its obligations hereunder.

     (iii) [Intentionally omitted]

     (iv) The Covered Securities and the certificates representing such Covered Securities are held by Stockholder, or by a nominee or custodian for the benefit of Stockholder, free and clear of all liens, claims, security interests, proxies, voting trusts or agreements, understandings or arrangements or any other encumbrances whatsoever, except for (A) any such encumbrances arising hereunder, or (B) any such encumbrances arising pursuant to the pledge of any Covered Securities by Stockholder to a financial institution or a brokerage firm (the “ Pledged Shares ”); provided, however, that Stockholder represents that any such arrangement regarding such Pledged Shares shall not prevent, delay or otherwise materially impair Stockholder’s ability to execute and deliver this Agreement or perform its obligations hereunder and Stockholder shall use its reasonable efforts to obtain an acknowledgment by the pledgee of the terms of this Agreement and such pledgee’s agreement to vote the Pledged Shares (if and to the extent the voting power of the Pledged Shares is being or to be exercised by pledgee) in accordance with Section 2.

     (v) No broker, investment banker, financial advisor or other person is entitled to any broker’s, finder’s, financial advisor’s or other similar fee or commission based upon arrangements made by or on behalf of Stockholder in connection with its entering into this Agreement. Stockholder shall have no obligation or liability of any kind with

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respect to any fee, commission or other amount of any kind incurred or payable by or on behalf of Petrohawk or Mission in connection with the Merger.

     (vi) Stockholder understands and acknowledges that Petrohawk is entering into the Merger Agreement in reliance upon Stockholder’s execution and delivery of this Agreement. Mission and Petrohawk understand and acknowledge that Stockholder is entering into this Agreement in reliance upon Petrohawk’s and Mission’s execution and delivery of the Merger Agreement and intended consummation of the Merger.

     (b) Petrohawk represents and warrants to Stockholder and Mission that:

     (i) The execution and delivery of this Agreement and the Merger Agreement (the “ Transaction Documents ”) by Petrohawk and the performance by Petrohawk of its obligations thereunder and the consummation of the transactions contemplated thereby have been duly authorized by all necessary action on the part of Petrohawk. Each of the Transaction Documents has been duly executed and delivered by, and constitutes a valid and binding agreement of, Petrohawk, enforceable against Petrohawk in accordance with its terms, except as enforcement may be limited by or subject to the effects of bankruptcy, insolvency, reorganization, moratorium and other laws relating to or affecting the rights of creditors and of general principles of equity.

     (ii) Neither the execution and delivery of the Transaction Documents nor the performance by Petrohawk of its obligations thereunder will result in a violation of, or a default under, or conflict with, (A) any provision of its certificate of incorporation, bylaws, partnership agreement, limited liability company agreement or similar organizational documents, (B) any contract, trust, commitment, agreement, understanding, arrangement or restriction of any kind to which Petrohawk is a party or bound, except, in the case of clause (B), as would not prevent, delay or otherwise materially impair Petrohawk’s ability to perform its obligations thereunder or consummate the Merger. Execution, delivery and performance of the Transaction Documents by Petrohawk will not violate, or require any consent, approval or notice under, any provision of any judgment, order, decree, statute, law, rule or regulation applicable to Petrohawk or the Covered Securities, except (x) for any reports under Sections 13(d) of the Exchange Act as may be required in connection with this Agreement and the transactions contemplated hereby or (y) as would not reasonably be expected to prevent, delay or otherwise materially impair Petrohawks’s ability to perform its obligations thereunder or consummate the Merger.

     (iii) There is no action, claim, suit, demand, hearing, notice of violation or deficiency, or proceeding (including any investigation or partial proceeding, such as a deposition), domestic or foreign, pending, or to the knowledge of Petrohawk threatened, that could prevent the consummation of, materially impair or materially delay the Merger or any of the transactions contemplated hereby.

     (c) Mission represents and warrants to Stockholder and Petrohawk that:

     (i) The execution and delivery of the Transaction Documents by Mission and the performance by Mission of its obligations thereunder and consummation of the

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transactions contemplated thereby have been duly authorized by all necessary action on the part of Mission. Each of the Transaction Documents has been duly executed and delivered by, and constitutes a valid and binding agreement of, Mission, enforceable against Mission in accordance with its terms, except as enforcement may be limited by or subject to the effects of bankruptcy, insolvency, reorganization, moratorium and other laws relating to or affecting the rights of creditors and of general principles of equity.

     (ii) Neither the execution and delivery of the Transaction Documents nor the performance by Mission of its obligations thereunder will result in a violation of, or a default under, or conflict with, (A) any provision of its certificate of incorporation, bylaws, partnership agreement, limited liability company agreement or similar organizational documents, (B)&n