Exhibit 99.4

INTERCREDITOR AGREEMENT

dated as of August 8, 2008,

among

QUICKSILVER RESOURCES INC.,
as the Borrower,

ITS SUBSIDIARIES PARTY HERETO,

JPMORGAN CHASE BANK, N.A. ,
as the First Lien Collateral Agent

and

CREDIT SUISSE,
as the Second Lien Collateral Agent

[CS&M Ref No. 05865-651]

TABLE OF CONTENTS

     INTERCREDITOR AGREEMENT dated as of August 8, 2008, among QUICKSILVER RESOURCES INC., a Delaware corporation (the “ Borrower ”), the SUBSIDIARIES of the Borrower whose signatures appear below or who in the future become parties hereto as provided in Section 10.14, JPMORGAN CHASE BANK, N.A., in its capacity as global administrative agent for the First Lien Secured Parties (in such capacity, together with its successors and assigns in such capacity, the “ First Lien Collateral Agent ”), and CREDIT SUISSE, Cayman Islands branch, in its capacity as administrative agent for the Term Lenders and as collateral agent for the Second Lien Secured Parties (in such capacity, together with its successors and assigns in such capacity, the “ Second Lien Collateral Agent ”). Capitalized terms used in this Agreement have the meanings assigned to them in Article I below.

               On the date hereof, the Borrower, the Term Lenders and Credit Suisse, Cayman Islands branch, as administrative agent, are entering into the Term Credit Agreement. Prior to the date hereof, the Borrower, Quicksilver Canada, the First Lien Consenting Lenders, the First Lien Global Administrative Agent and the First Lien Canadian Administrative Agent entered into the First Lien Fifth Amendment, which shall become effective on the date hereof.

               The First Lien Fifth Amendment provides that the Second Priority Liens may be granted to the Second Lien Collateral Agent only if such Liens are subject to the terms of an intercreditor agreement in the form of this Agreement.

               The Existing Senior Notes Indenture provides that the US Grantors may not create, incur or suffer to exist Liens on the Collateral created under the Term Security Documents unless such Liens are “Permitted Liens” under and as defined in the Existing Senior Notes Indenture or, contemporaneously with the incurrence of such Liens, effective provision is made to secure the Existing Senior Notes Obligations equally and ratably with the indebtedness secured by such Liens for so long as such indebtedness is so secured.

               The Term Security Documents create, in favor of the Second Lien Collateral Agent, for the benefit of the Term Secured Parties and the Existing Senior Notes Secured Parties, Liens on the Second Lien Collateral described therein as security for the indefeasible payment in full in cash and performance of the Term Obligations and the Existing Senior Notes Obligations.

               In consideration of the foregoing and the mutual covenants and obligations herein set forth and for other good and valuable consideration, the sufficiency and receipt of which are hereby acknowledged, the parties hereto, intending to be legally bound, hereby agree as follows:

ARTICLE I

Definitions

               SECTION 1.01. Defined Terms . As used in the Agreement, the following terms shall have the meanings specified below:

               “ Affiliate ” of any person shall mean any person directly or indirectly Controlled by, Controlling or under common Control with such first Person. For purposes of this definition, the term “ Control ” shall means the possession, directly or indirectly, of the power to direct or cause the direction of the management or policies of a person, whether through the ability to exercise voting power, by contract or otherwise, but not solely by being an officer or director of such person, and the terms “ Controlling ” and “ Controlled ” shall have meanings correlative thereto.

               “ Agreement ” shall mean this Intercreditor Agreement.

               “ Amend ” shall mean, in respect of any agreement, to amend, restate, supplement, waive or otherwise modify such agreement, in whole or in part. The terms “ Amended ” and “ Amendment ” shall have correlative meanings.

               “ Bankruptcy Code ” shall mean Title 11 of the United States Code entitled “Bankruptcy,” as now and hereinafter in effect, or any successor statute.

               “ Bankruptcy Law ” shall mean the Bankruptcy Code and any other Federal, state or foreign bankruptcy, insolvency, receivership or similar law.

               “ Borrower ” shall have the meaning assigned to such term in the preamble.

               “ Business Day ” shall mean any day that is not a Saturday, Sunday or a United States federal holiday or any other day on which commercial banks in New York City are authorized or required by law to remain closed.

               “ Canadian Borrower ” shall mean Quicksilver Resources Canada Inc., an Alberta, Canada corporation.

               “ Cash Collateral ” shall have the meaning assigned to such term in Section 6.01(a)(i).

               “ Collateral ” shall mean, collectively, the First Lien US Collateral and the Second Lien Collateral.

               “ Collateral Agents ” shall mean the First Lien Collateral Agent and the Second Lien Collateral Agent.

               “ Comparable Second Lien Security Document ” shall mean, in relation to any Collateral subject to any Lien created under any First Lien Security Document, the

Second Lien Security Document that creates a Lien on the same Collateral, granted by the same US Grantor.

               “ DIP Financing ” shall have the meaning assigned to such term in Section 6.01(a)(ii).

               “ DIP Financing Liens ” shall have the meaning assigned to such term in Section 6.01(a)(ii).

               “ Discharge of First Lien Obligations ” shall mean, subject to Sections 7.02 and 7.04, (a) payment in full in cash of the principal of and interest on (including interest accruing during the pendency of any Insolvency or Liquidation Proceeding, regardless of whether allowed or allowable in such Insolvency or Liquidation Proceeding), and premium, if any, on, all Indebtedness outstanding under the First Lien Loan Documents, (b) payment in full of all other First Lien Obligations that are due and payable or otherwise accrued and owing at or prior to the time such principal and interest are paid, (c) cancellation of or the entry into arrangements satisfactory to the First Lien Global Administrative Agent and each applicable issuing bank with respect to all letters of credit issued and outstanding under the First Lien Credit Agreements (any such arrangement in the form of cash collateralization to be in an amount not greater than 105% of the aggregate undrawn face amount of such letters of credit), (d) cancellation of or the entry into arrangements satisfactory to the First Lien Global Administrative Agent and each applicable hedging counterparty with respect to all obligations under Hedging Agreements that constitute First Lien Obligations and (e) termination or expiration of all commitments to lend under the First Lien Credit Agreements.

               “ Disposition ” shall mean any sale, lease, exchange, transfer or other disposition. “ Dispose ” shall have a correlative meaning.

               “ Domestic Subsidiary ” shall mean any Subsidiary other than a Foreign Subsidiary.

               “ Equity Interests ” shall mean, with respect to any person, shares of the capital stock, partnership interests, membership interests in a limited liability company, beneficial interests in a trust or other equity interests in such person, or any warrants, options or other rights to acquire any of the foregoing.

               “ Exercise of a Buy-Out Right ” shall have the meaning assigned to such term in Section 3.01(d).

               “ Existing Senior Notes ” shall mean the 8 ¹ / 4 % Senior Notes due 2015 of the Borrower issued under the Existing Senior Notes Indenture.

               “ Existing Senior Notes Fifth Supplemental Indenture ” shall mean the Fifth Supplemental Indenture dated as of June 27, 2008, by and among the Borrower, the Subsidiary Guarantors party thereto and The Bank of New York Mellon Trust Company, N.A., as trustee.

               “ Existing Senior Notes Indenture ” shall mean the Indenture dated as of December 22, 2005, between the Borrower and The Bank of New York Mellon Trust Company, N.A. (as successor in interest to JPMorgan Chase Bank, National Association), as trustee, as supplemented by the Existing Senior Notes Fifth Supplemental Indenture and the Existing Senior Notes Sixth Supplemental Indenture.

               “ Existing Senior Notes Obligations ” means Indebtedness (as defined in the Existing Senior Notes Indenture as in effect on the date hereof) due with respect to (a) the Existing Senior Notes and (b) the Subsidiary Guarantee (as defined in the Existing Senior Notes Indenture as in effect on the date hereof) of any US Grantor.

               “ Existing Senior Notes Secured Parties ” shall mean “Holders”, as defined in the Existing Senior Notes Indenture.

               “ Existing Senior Notes Sixth Supplemental Indenture ” shall mean the Sixth Supplemental Indenture dated as of July 10, 2008, by and among the Borrower, the Subsidiary Guarantors party thereto and The Bank of New York Mellon Trust Company, N.A., as trustee.

               “ First Lien Canadian Administrative Agent ” shall mean JPMorgan Chase Bank, N.A., Toronto Branch, in its capacity as the Canadian administrative agent under the First Lien Canadian Credit Agreement, together with its successors and assigns in such capacity.

               “ First Lien Canadian Credit Agreement ” shall mean the Amended and Restated Credit Agreement dated as of February 9, 2007, among the Canadian Borrower, the lenders party thereto, BNP Paribas and Bank of America, N.A., as co-global syndication agents, Fortis Capital Corp., The Bank of Nova Scotia and Deutsche Bank Trust Company Americas, as co-global documentation agents, JPMorgan Chase Bank, N.A., Toronto Branch, as Canadian administrative agent, and JPMorgan Chase Bank, N.A., as global administrative agent.

               “ First Lien Canadian Lenders ” shall mean, at any time, persons that are at such time “Lenders” under and as defined in the First Lien Canadian Credit Agreement.

               “ First Lien Collateral Agent ” shall have the meaning assigned to such term in the preamble.

               “ First Lien Consenting Lenders ” shall mean, collectively, (a) each First Lien Lender that is a party to the First Lien Fifth Amendment and (b) each person that becomes a First Lien Lender (including pursuant to the provisions of Section 7.02) after the date of the First Lien Fifth Amendment (other than any such person that (i) is (A) a Lender Affiliate (as defined in the First Lien US Credit Agreement as of the date hereof) of a First Lien Non-Consenting Lender or (B) an Approved Fund (as defined in the First Lien US Credit Agreement as of the date hereof) that is administered or managed by a

First Lien Non-Consenting Lender, a Lender Affiliate of a First Lien Non-Consenting Lender or a person or Affiliate of a person that administers or manages a First Lien Non-Consenting Lender and (ii) becomes a First Lien Lender as an assignee of a First Lien Non-Consenting Lender), together with their respective successors and assigns.

               “ First Lien Credit Agreements ” shall mean the First Lien US Credit Agreement and the First Lien Canadian Credit Agreement.

               “ First Lien Fifth Amendment ” shall mean the Fifth Amendment to Combined Credit Agreements, dated as of August 4, 2008, among the Borrower, Quicksilver Canada, the First Lien Lenders party thereto, the First Lien Global Administrative Agent and the First Lien Canadian Administrative Agent.

               “ First Lien Global Administrative Agent ” shall mean JPMorgan Chase Bank, N.A., in its capacity as the global administrative agent under the First Lien Credit Agreements, together with its successors and assigns in such capacity.

               “ First Lien Global Borrowing Base ” shall mean “Global Borrowing Base”, as defined in the First Lien Credit Agreements (or, in respect of any New First Lien Loan Documents, a term connoting a meaning substantially similar to that connoted by the term “Global Borrowing Base” under the First Lien Credit Agreements as of the date hereof).

               “ First Lien Intercreditor Agreement ” shall mean the Amended and Restated Intercreditor Agreement dated as of February 9, 2007, among the First Lien Lenders, the First Lien Global Administrative Agent, the First Lien Canadian Administrative Agent and certain other persons party thereto.

               “ First Lien Lenders ” shall mean (a) the First Lien US Lenders and (b) the First Lien Canadian Lenders.

               “ First Lien Loan Documents ” shall mean the “Loan Documents”, as defined in any First Lien Credit Agreement.

               “ First Lien Obligations ” shall mean the “Combined Obligations”, as defined in the First Lien US Credit Agreement.

               “ First Lien Non-Consenting Lender ” shall mean (a) for purposes of the definition of the term “First Lien Consenting Lender”, each person that is a First Lien Lender as of the date of the First Lien Fifth Amendment but is not a party to the First Lien Fifth Amendment, and (b) for all other purposes of this Agreement, each First Lien Lender that is not a First Lien Consenting Lender.

               “ First Lien Required Lenders ” shall mean the “Majority Lenders”, as defined in the First Lien US Credit Agreement as of the date hereof.

               “ First Lien Secured Parties ” shall mean (a) the First Lien Lenders, (b) the First Lien Global Administrative Agent, (c) the First Lien Canadian Administrative Agent, (d) the First Lien Collateral Agent, (e) each other person to whom any of the First Lien Obligations (including First Lien Obligations under Hedging Agreements and indemnification obligations) is owed and (f) the successors and assigns of each of the foregoing.

               “ First Lien Security Documents ” shall mean any and all agreements, documents or instruments now existing or entered into after the date hereof that grant a Lien on any assets of any US Grantor to secure any First Lien Obligations or under which rights or remedies with respect to any such Lien are governed.

               “ First Lien Subsidiary Guarantee ” shall mean, in respect of any US Grantor, the Guarantee by such US Grantor of the First Lien Obligations pursuant to the First Lien Loan Documents.

               “ First Lien US Collateral ” shall mean any assets of any US Grantor that constitute “Collateral” or “Mortgaged Property” as defined in the First Lien Security Documents, and any other assets of any US Grantor now or at any time hereafter subject to a Lien securing any First Lien Obligation.

               “ First Lien US Credit Agreement ” shall mean the Amended and Restated Credit Agreement dated as of February 9, 2007, among the Borrower, the lenders party thereto, BNP Paribas and Bank of America, N.A., as co-global syndication agents, Fortis Capital Corp., The Bank of Nova Scotia and Deutsche Bank Trust Company Americas, as co-global documentation agents, and JPMorgan Chase Bank, N.A., as global administrative agent.

               “ First Lien US Lenders ” shall mean, at any time, persons that are at such time “Lenders” under and as defined in the First Lien US Credit Agreement.

               “ First Priority Liens ” shall mean all Liens on the Collateral securing the First Lien Obligations, whether created under the First Lien Security Documents or acquired by possession, statute (including any judgment lien), operation of law, subrogation, pursuant to the terms of this Agreement or otherwise.

               “ Foreign Subsidiary ” shall mean any Subsidiary that is organized under the laws of a jurisdiction other than the United States of America, any State thereof or the District of Columbia.

               “ GAAP ” shall mean generally accepted accounting principles in the United States of America, as in effect from time to time.

               “ Governmental Authority ” shall mean the government of the United States of America, Canada, any other nation or any political subdivision thereof, whether state, provincial, territorial or local, and any agency, authority, instrumentality, regulatory

body, court, central bank or other entity exercising executive, legislative, judicial, taxing, regulatory or administrative powers or functions of or pertaining to government.

               “ Guarantee ” shall mean “Guarantee”, as defined in the First Lien US Credit Agreement as of the date hereof.

               “ Hedging Agreement ” shall mean any agreement, instrument, arrangement or schedule or supplement thereto evidencing any Hedging Transaction.

               “ Hedging Transaction ” shall mean any financial derivative transaction, including any commodity, interest rate, currency or other derivative, swap, option, collar, futures contract or other contract pursuant to which a person hedges risks related to commodity prices, interest rates, currency exchange rates, securities prices or financial market conditions.

               “ Indebtedness ” shall mean “Indebtedness”, as defined in the First Lien US Credit Agreement as of the date hereof.

               “ Insolvency or Liquidation Proceeding ” shall mean (a) any voluntary or involuntary proceeding under the Bankruptcy Code or any other Bankruptcy Law with respect to any US Grantor, (b) any voluntary or involuntary appointment of a receiver, trustee, custodian, sequestrator, conservator or similar official for any US Grantor or for a substantial part of the property or assets of any US Grantor, (c) any voluntary or involuntary winding-up or liquidation of any US Grantor or (d) any general assignment for the benefit of creditors by any US Grantor.

               “ Lien ” shall mean, with respect to any asset, any lien, charge or security interest arising from a mortgage, encumbrance, pledge, security agreement, conditional sale or trust receipt or a lease, consignment, bailment or margin account for security purposes.

               “ Loan Documents ” shall mean the First Lien Loan Documents and the Second Lien Loan Documents.

               “ New First Lien Collateral Agent ” shall have the meaning assigned to such term in Section 7.02.

               “ New First Lien Loan Documents ” shall have the meaning assigned to such term in Section 7.02.

               “ New First Lien Obligations ” shall have the meaning assigned to such term in Section 7.02.

               “ Obligations ” shall mean the First Lien Obligations and the Second Lien Obligations.

               “ person ” shall mean any natural person, corporation, limited liability company, trust, joint venture, association, company, partnership, Governmental Authority or other entity.

               “ Quicksilver Canada ” shall mean Quicksilver Resources Canada Inc., an Alberta, Canada corporation.

               “ Pledged or Controlled Collateral ” shall have the meaning assigned to such term in Article V.

                “Refinance ” shall mean, in respect of any Indebtedness, to refinance, extend, renew, restructure or replace, or to issue other Indebtedness in exchange or replacement for, such Indebtedness, in whole or in part. “ Refinanced ” and “ Refinancing ” shall have correlative meanings.

               “ Refinancing Notice ” shall have the meaning assigned to such term in Section 7.02.

               “ Release ” shall have the meaning assigned to such term in Section 3.04(a).

               “ Second Lien Collateral ” shall mean any assets of any US Grantor that constitute “Collateral” or “Mortgaged Property” as defined in the Second Lien Security Documents, and any other assets of any US Grantor now or at any time hereafter subject to a Lien securing any Term Obligations.

               “ Second Lien Collateral Agent ” shall have the meaning assigned to such term in the preamble.

               “ Second Lien Loan Documents ” shall mean the Term Loan Documents and the Existing Senior Notes Indenture.

               “ Second Lien Obligations ” shall mean the Term Obligations and the Existing Senior Notes Obligations.

               “ Second Lien Permitted Actions ” shall have the meaning assigned to such term in Section 3.01(a).

               “ Second Lien Secured Parties ” shall mean the Term Secured Parties and the Existing Senior Notes Secured Parties.

               “ Second Lien Security Documents ” shall mean (a) the Term Security Documents and (b) any and all agreements, documents or instruments now existing or entered into after the date hereof that grant in favor of the Second Lien Collateral Agent, for the benefit of the Second Lien Secured Parties, or directly in favor of any Term Secured Party, a Lien on any assets of any US Grantor to secure any Second Lien Obligations or under which rights or remedies with respect to any such Lien are governed.

               “ Second Priority Liens ” shall mean (a) all Liens on the Collateral securing the Second Lien Obligations created under the Second Lien Security Documents and (b) all other Liens on the Collateral securing the Term Obligations, whether acquired by possession, statute (including any judgment lien), operation of law, subrogation or otherwise.

               “ Security Documents ” shall mean the First Lien Security Documents and the Second Lien Security Documents.

               “ Standstill Period ” shall have the meaning assigned to such term in Section 3.02(a).

               “ Subsidiary ” shall mean, with respect to any person (the “ parent ”) at any date, any corporation, limited liability company, partnership (limited or general), association or other entity the accounts of which would be consolidated with those of the parent in the parent’s consolidated financial statements if such financial statements were prepared in accordance with GAAP as of such date. Unless otherwise indicated herein, each reference to the term “Subsidiary” shall mean a Subsidiary of the Borrower.

               “ Term Administrative Agent ” shall mean Credit Suisse, Cayman Islands branch, in its capacity as the administrative agent under the Term Credit Agreement, together with its successors and assigns in such capacity.

               “ Term Credit Agreement ” shall mean the Credit Agreement dated as of August 8, 2008, among the Borrower, the lenders party thereto and Credit Suisse, Cayman Islands branch, as administrative agent.

               “ Term Lenders ” shall mean, at any time, persons that are at such time “Lenders” under and as defined in the Term Credit Agreement.

               “ Term Loan Documents ” shall mean the “Loan Documents”, as defined in the Term Credit Agreement.

               “ Term Obligations ” shall mean “Obligations”, as defined in the Term Credit Agreement.

               “ Term Required Lenders ” shall mean the “Required Lenders”, as defined in the Term Credit Agreement as of the date hereof.

               “ Term Secured Parties ” shall mean (a) the Term Lenders, (b) the Term Administrative Agent, (c) the Second Lien Collateral Agent, (d) each other person to whom any of the Term Obligations (including indemnification obligations) is owed and (e) the successors and assigns of each of the foregoing.

               “ Term Security Documents ” shall mean any and all agreements, documents or instruments now existing or entered into after the date hereof that grant a

Lien on any assets of any US Grantor to secure any Term Obligations or under which rights or remedies with respect to any such Lien are governed.

               “ Term Subsidiary Guarantee ” shall mean, in respect of any US Grantor, the Guarantee by such US Grantor of the Term Obligations pursuant to the Term Loan Documents.

               “ Uniform Commercial Code ” or “ UCC ” shall mean the Uniform Commercial Code (or any similar or equivalent legislation) as in effect from time to time in any applicable jurisdiction.

               “ US Grantors ” means, at any time, the Borrower and each Domestic Subsidiary that, at such time, (a) pursuant to any First Lien Security Document has granted a Lien to secure any First Lien Obligations and (b) pursuant to any Second Lien Security Document has granted a Lien to secure any Second Lien Obligations; provided , however , that solely for purposes of Section 2.03, a Domestic Subsidiary shall be deemed to be a “US Grantor” so long as it satisfies either clause (a) or (b) above (even if it does not satisfy both clauses (a) and (b) above) so long as such Domestic Subsidiary is required pursuant to the terms of the First Lien Loan Documents and the Term Loan Documents to grant a Lien on assets owned by it to secure the First Lien Obligations and the Term Obligations, respectively.

               SECTION 1.02. Terms Generally . The definitions of terms herein shall apply equally to the singular and plural forms of the terms defined. Whenever the context may require, any pronoun shall include the corresponding masculine, feminine and neuter forms. The words “include”, “includes” and “including” shall be deemed to be followed by the phrase “without limitation”. The word “will” shall be construed to have the same meaning and effect as the word “sh