##### 



EXHIBIT 1.1
 Execution Copy
 Quicksilver Gas Services LP    Underwriting Agreement




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Underwriting Agreement
  as Representatives
 
  Partnership Schedule A Underwriters UBS Goldman Representatives Firm Units Partnership
Units Additional Units Units Agreement General Partner Holdings Quicksilver Quicksilver Parties Schedule B Subsidiaries Partnership Entities
 Offering DUP
Manager Directed Unit Program Reserved Units Directed Unit Participants




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NASD
 Securities Act SEC
 Registration Statement Effective Time
 Preliminary Prospectus
 Prospectus
 Permitted Free Writing Prospectuses Road Show
 2




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Disclosure Package
 business day NYSE
 Exchange
Act Exchange Act Registration Statement
 Cowtown Pipeline Cowtown Plant Pipeline LP Processing
LP
  1.
    
    Pipeline LP and Processing LP formed Holdings to act as the
holding company for Quicksilvers interest in the Partnership;2.
    
    Holdings formed Quicksilver Gas Services Operating GP LLC, a
Delaware limited liability company (Quicksilver OPGP) to act as the
general partner of each of Cowtown Pipeline Partners L.P. (Pipeline
Partners) and Cowtown Gas Processing Partners L.P. (Processing
Partners);3.
    
    Holdings formed the General Partner to act as the general
partner of the Partnership;4.
    
    The General Partner and Holdings formed the Partnership; and5.
    
    The Partnership formed Quicksilver Gas Services Operating LLC,
a Delaware limited liability company (Quicksilver Operating LLC) to
become a subsidiary of the Partnership and to indirectly own all of the
interests in the Partnerships assets.
 Prior Transactions
 3




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1.
    
    Pipeline LP will make a capital contribution to Holdings of its
1.0% general partner interest and 92.0% limited partner interest in Pipeline
Partners in exchange for a continuation of its member interest in Holdings;2.
    
    Processing LP will make a capital contribution to Holdings of
its 1.0% general partner interest and 94.0% limited partner interest in
Processing Partners in exchange for a continuation of its member interest in
Holdings;3.
    
    Holdings will make a capital contribution to Quicksilver OPGP
of the 1.0% general partner interests in each of Pipeline Partners and
Processing Partners in exchange for a continuation of its member interest in
Quicksilver OPGP;4.
    
    The Partnership will enter into a $150 million revolving credit
facility with Bank of America, N.A., as administrative agent, and the other
lenders named therein (collectively with the other financing documents entered
into in connection therewith, the Credit Facility);5.
    
    Holdings will convey to the General Partner, as a capital
contribution, a part of its limited partner interests in each of Pipeline
Partners and Processing Partners with an aggregate value equal to 2.0% of the
equity value of the Partnership;6.
    
    The General Partner will convey to the Partnership, as a
capital contribution, its limited partner interests in each of Pipeline
Partners and Processing Partners in exchange for (a) 415,614 general partner
units representing a continuation of its 2.0% general partner interest in the
Partnership and (b) all of the Incentive Distribution Rights (as defined in the
Partnership Agreement);7.
    
    Holdings will convey to the Partnership, as a capital
contribution, all of its interest in Quicksilver OPGP and the rest of its
limited partner interests in each of Pipeline Partners and Processing Partners
in exchange for (a) 11,513,625 subordinated units representing limited partner
interests and 5,696,752 Common Units representing limited partner interests,
with an aggregate 73.2% limited partner interest in the Partnership, and (b)
the right to receive approximately $162.1 million in cash in part to reimburse
it for certain capital expenditures incurred by it or its affiliate;8.
    
    The Private Investors will convey, as a capital contribution,
their limited partner interests in each of Pipeline Partners and Processing
Partners in exchange for (a) an aggregate 816,873 common units representing an
aggregate 3.5% limited partner interest in the Partnership, and (b) the right
to receive approximately $7.7 million in cash in part for reimbursement for
certain capital expenditures incurred by the Private Investors;
 4




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9.
    
    The public, through the underwriters, will contribute $97.635
million in cash, $105.0 million of gross proceeds, net of the Underwriters
discounts and commissions and a structuring fee (the Offering
Proceeds), to the Partnership in exchange for 5,000,000 million Common
Units representing an 21.3% limited partner interest in the Partnership (the
Offering);10.
    
    The Partnership will enter into a $50 million subordinated
intercompany note with Quicksilver (the Quicksilver Note) to finance
a portion of the expenses associated with the Offering;11.
    
    The Partnership will use the Offering Proceeds and the cash
contribution from the General Partner and the Quicksilver Note to (i) pay the
underwriters structuring fee, (ii) pay approximately $3.0 million in offering
expenses (net of the Underwriters discounts and commissions and structuring
fees) incurred by Holdings on behalf of the Partnership, and (iii) distribute
approximately $162.1 million, consisting of $112.1 million in cash and the $50
million Quicksilver Note, to Quicksilver and $7.7 million in cash to the
Private Investors as reimbursement for capital expenditures comprising most of
the initial investment by Quicksilver and the Private Investors in the
Partnership;12.
    
    The Partnership will convey to Quicksilver Operating LLC, as a
capital contribution, its limited partner interests in each of Pipeline
Partners and Processing Partners and its interest in Quicksilver OPGP;13.
    
    The agreements of limited partnership and the limited liability
company agreements of the aforementioned entities will be amended and restated
to the extent necessary to reflect the foregoing transactions and any other
transactions contemplated by the Contribution Documents (as defined below);14.
    
    If the Underwriters exercise their option to purchase any
Option Units within 30 days after the date of this Agreement as provided in
Section 4, the Partnership will use the net proceeds of the sale of those
Option Units for general partnership purposes; and15.
    
    The Partnership will redeem the limited partner interest in the
Partnership acquired by Holdings in exchange for the amount of the initial cash
capital contribution by Holdings.
 Transactions Contribution Documents
 5




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Omnibus Agreement Services Agreement Processing Agreement Transaction Documents
 Organizational Documents Operative Documents
  Sale and Purchase Schedule A Section 9
 Over-Allotment Option additional time of purchase provided however
 6




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Schedule A Section 9
 Payment and Delivery DTC Section
9 time of purchase
  Section 7
 Representations and Warranties of the Partnership
 Registration; No Material Misstatements or Omissions
 7




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provided, however Section 3(a) Section 11
 8




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Prospectuses Used in Offering prospectus bona fide
 Formation and Qualification of Partnership Entities
 Foreign Qualification and Registration
 9




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Material Adverse Effect Schedule C
 Ownership of the General Partner General Partner LLC Agreement
 Ownership of the General Partner Interest in the Partnership GP Interest
 Ownership of the Sponsor Units Sponsor Units Delaware LP Act
 Ownership of Quicksilver Operating LLC
 10




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Quicksilver Operating LLC Agreement
 Ownership of Quicksilver OPGP Quicksilver OPGP LLC Agreement
 Subsidiaries
 Valid Issuance of Units
 11




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Conformity to Description of Partnership Units
 Authorization, Execution and Delivery of this Agreement
 Authorization, Execution, Delivery and Enforceability of Certain Agreements
      12




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No Conflicts or Violations; No Default
 13




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Clauses (B) (C) (D) (E) clauses (II) (III) (IV) (V)
 No Consents Regarding the Offering Consent
 14




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No Preemptive Rights, Registration Rights, Options or Other Rights
 Permits
 Descriptions; Exhibits
 15




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Litigation
 Independent Registered Public Accounting Firms
 Financial Statements
 16




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No Material Adverse Change
 Lock-Up Agreement Lock-Up Agreement Exhibit A Exhibit
A-1
 Investment Company
 17




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Investment Company Act
 Title to Properties
 Information Underlying Reserve Report of Quicksilver Schlumberger Reserve Report Letter
 Independent Petroleum Engineers
 Rights-of-Way rights-of-way
 18




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Intellectual Property Intellectual Property
 Labor and Employment ERISA
 Environmental Compliance
 19




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Environmental Laws Proceedings CERCLA Hazardous Materials
 Environmental Compliance Review
 Tax Returns
 20




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Insurance
 No Business Interruptions
 Non-Renewal of Agreements; No Third Party Defaults
 Internal Controls
 Disclosure Controls
 21




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Related Party Transactions
 Forward-Looking Statements
 Statistical and Market-Related Data
 No Prohibition on Distributions
 22




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Foreign Corrupt Practices Act.
 Money Laundering Laws. Money Laundering Laws
 No Other Securities
 NYSE Arca Listing
 No Brokers Fees
 No Stabilizing Transactions
 23




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NASD Affiliations
 Directed Unit Program
 Reserved Unit Sales
 No Distribution of Other Offering Materials
  Certain Covenants of the Partnership
 Blue Sky Qualification
 24




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provided however
 Copies of Prospectus
 Effectiveness of Registration Statement
 Delivery of Prospectus
 25




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Filing of Amendments or Supplements
 Exchange Act Reports Section 4(e)
 Rule 462(b) Registration Statement
 Misstatements and Omissions Section 4(e)
 26




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Earnings Information
 Annual Report EDGAR
 Copies of the Registration Statement
 Copies of Other Documents
 Interim Financial Statements
 Application of Proceeds
 27




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Compliance with Rules 433(d) and (g)
 Partnership Lock-Up Lock-Up Period clause (i) (ii) (iii) provided however Section 4(p)
 Lock-Up Agreements and Restrictions Exhibit A-1
 28




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Press Releases and Other Communications
 Distribution of Prospectuses
 No Stabilization
 NYSE Arca Listing
 Transfer Agent
 Covenant to Pay Costs
 29




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provided however Section 5 Section 6
 Reimbursement of Underwriters Expenses
 Conditions of Underwriters Obligations
 Exhibit B
 30




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31




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Exhibit C
 Section 4(q)
    32




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Effective Date of Agreement; Termination
 clause (D) (E)
  Sections 5 6 10 Section 10
 Increase in Underwriters Commitments Sections 7 8 Section
7
 33




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Section 8 Section 1 Schedule A
   Underwriter Schedule A
  Indemnity and Contribution
  34




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Section 11 Section 10 Section 11 clause (iii)
 Section 10
 35




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clauses (i) (iii) Section 10(a) provided clause
(3) Section 10(a) Section
10(a)
 Section 11 Section 11
 36




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Proceeding indemnified party indemnifying
party subsection (a) (b) Section 10 provided however Section 10(a) Section
10(c)
 37




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Section 10 subsections (a) (c) Section 10 clause (i) clause (i)
 Section 10 subsection (d) Section 10 Section
10
 38




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Section 10
 Information Furnished by the Underwriters
 Notices
 Governing Law; Construction
 Submission to Jurisdiction
 39




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Parties at Interest
 No Fiduciary Relationship
 Counterparts
 Successors and Assigns
 40




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Miscellaneous
 [ The Remainder of This Page Intentionally Left Blank; Signature Page Follows ]
 41




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Very truly yours,QUICKSILVER GAS SERVICES LPBy:
    
    Quicksilver Gas Services GP LLC,
its general partnerBy:
    
    /s/ John C. CironeName: John C. CironeTitle: Senior Vice President, General Counsel
and SecretaryQUICKSILVER GAS SERVICES GP LLCBy:
    
    /s/ John C. CironeName: John C. CironeTitle: Senior Vice President, General Counsel
and SecretaryQUICKSILVER GAS SERVICESHOLDINGS LLCBy:
    
    /s/ John C. CironeName: John C. CironeTitle: Senior Vice President, General Counsel
and SecretaryQUICKSILVER RESOURCES INC.By:
    
    /s/ John C. CironeName: John C. CironeTitle: Senior Vice President, General Counsel
and Secretary
 42




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Accepted and agreed to as of the date first above
written, on behalf of themselves and the other
several Underwriters named in Schedule AUBS SECURITIES LLCGOLDMAN, SACHS & CO.A.G. EDWARDS & SONS, INC.FORTIS SECURITIES LLCJ.P. MORGAN SECURITIES INC.By:
    
    UBS SECURITIES LLCBy:
    
    /s/ Michael JamiesonName:
Michael JamiesonTitle: Managing DirectorBy:
    
    /s/ Drew HornName:
Drew HornTitle: DirectorBy:
    
    GOLDMAN, SACHS & CO.By:
    
    /s/ Goldman,
Sachs & Co.(Goldman,
Sachs & Co.)
 43




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SCHEDULE A
 Number ofUnderwriter
    
    Firm UnitsUBS Securities LLC
    
    
    1,875,000Goldman, Sachs & Co
    
    
    1,875,000J.P. Morgan Securities Inc.
    
    
    500,000A.G. Edwards & Sons, Inc.
    
    
    500,000Fortis Securities LLC
    
    
    250,000Total
    
    
    5,000,000




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SCHEDULE B
 Subsidiaries
 JurisdictionSubsidiary
    
    of FormationQuicksilver Gas Services Operating LLC
    
    DEQuicksilver Gas Services Operating GP LLC
    
    DECowtown Pipeline Partners L.P.
    
    TXCowtown Gas Processing Partners L.P.
    
    TX




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SCHEDULE C
 Jurisdictions of Foreign Qualification or Registration
 Entities
    
    Foreign JurisdictionsQuicksilver Gas Services LP
    
    TXQuicksilver Gas Services GP LLC
    
    TXQuicksilver Gas Services Operating LLC
    
    TXQuicksilver Gas Services Operating GP LLC
    
    TXCowtown Pipeline Partners L.P.
    
    NoneCowtown Gas Processing Partners L.P.
    
    NoneCowtown Pipeline L.P.
    
    NoneCowtown Gas Processing L.P.
    
    None




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SCHEDULE D
 Permitted Free Writing Prospectuses
 1.
    
    Electronic Road Show on www.netroadshow.com and www.retailroadshow.com.




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EXHIBIT A
 Form of Lock-Up Agreement
 
 Schedule A
 
 
  Underwriting Agreement Representatives Schedule A Offering Partnership Units
 Lock-Up Period SEC Exchange Act
 Exhibit A-1




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Exhibit B-2




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Yours very truly,Name:Title:
 Exhibit B-3




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EXHIBIT A-1
 List of Parties to Execute Lock-Up Agreements
 Name
    
    Position with General Partner1. Quicksilver Resources Inc.2. Quicksilver Gas Services
Holdings LLC3. Quicksilver Gas Services GP
LLC4. Thomas F. Darden
    
    President, Chief Executive Officer and Director5. Glenn Darden
    
    Chairman of the Board6. Paul J. Cook
    
    Executive Vice President   Chief Operating Officer and Director7. Philip W. Cook
    
    Senior Vice President - Chief Financial Officer and Director8. John C. Cirone
    
    Senior Vice President, General Counsel and Secretary9. D. Wayne Blair
    
    Vice President - Chief Accounting Officer10. Alvin Bledsoe
    
    Director11. Philip D. Gettig
    
    Director12. John W. Somerhalder II
    
    Director13. Little Hoss Cowtown Pipeline
Partners, L.P.14. Little Hoss Cowtown
Processing Partners, L.P.15. LGS  Godley Investments, LLC
 Exhibit A-1-1




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EXHIBIT B
 Form of Opinion of Andrews Kurth LLP
 
 
 
 
 Public Offering of Common Units issued by Quicksilver Gas Services LP
  Quicksilver Underwriting Agreement Issuer General Partner Holdings Underwriters Firm]
Securities Limited
Partner Interests Option
Securities Securities 1
  
 1
    
    To be deleted if the option has been
exercised in full and there will be a single closing for all securities
(including those purchased pursuant to the option) to be issued pursuant to the
Underwriting Agreement. Exhibit B-1




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2 Securities Act SEC Rules and Regulations Registration Statement
 Rule 462(b)
Registration Statement    3
 Preliminary Prospectus Disclosure Package
 Prospectus
   Contribution Agreement Quicksilver
OPGP Quicksilver Operating
 Omnibus Agreement
 
 2
    
    Include if the offering is increased pursuant
to Rule 462(b) under the Securities Act of 1933.3
    
    Include if the offering is increased pursuant
to Rule 462(b) under the Securities Act of 1933. Exhibit B-2




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Secondment
Agreement
 Exchange Agreement Pipeline Processing
 Gas Processing Agreement Pipeline Partners Processing Partners
 Issuer Certificate of Limited Partnership
 Original Issuer LP Agreement Amended and
Restated Issuer LP Agreement
 
 General Partner Certificate of Formation
  Exhibit B-3




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General Partner LLC Agreement
 Holdings Certificate of
Formation
 Holdings LLC Agreement
 
 Quicksilver Certificate of
Incorporation
 Quicksilver Bylaws
 
 Quicksilver Operating
Certificate of Formation
  Exhibit B-4




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Quicksilver Operating
LLC Agreement
 
 Quicksilver OPGP Certificate of Formation
 Quicksilver OPGP LLC Agreement
 
 Pipeline Partners Certificate of Limited Partnership
 Pipeline Partners LP Agreement
 Processing Partners Certificate of Limited Partnership
 Exhibit B-5




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Processing Partners LP Agreement
 Management Pipeline Certificate of Limited
Partnership
 Pipeline LP Agreement
 Processing Certificate of Limited Partnership
 Processing LP
Agreement
 Management Articles of Incorporation
 Management Bylaws
 Exhibit B-6




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Opinion Support Certificate
 4 Search Results 5
 6
   
 4
    
    The as of date may precede the
date of the searches reflecting a delay between when filings are made and when
they are reflected in the Secretary of States records.5
    
    Description to be modified based upon review
of Search Results.6
    
    Delete if the Opinion Support Certificate
establishes that there are no Applicable Orders. Exhibit B-7




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Applicable Agreements
 Applicable Orders
 Charter Documents
 Credit Agreement
 Intercompany Agreements
 MLP Entities
 Operational Agreements
 Organizational Agreements
 Exhibit B-8




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Organizational Documents
 Person
 Principal Issuer Subsidiaries
 Quicksilver Entities
 Senior Cowtown Entities
        Exhibit B-9




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DLLCA Liens
 
 
  Exhibit B-10




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Sponsor Units DRULPA
    Exhibit B-11




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Exhibit B-12




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DGCL TBCA TBOC TRLPA
  Exhibit B-13




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Governmental Approval
    [Firm] investment company
  Exhibit B-14




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7 8
 9
 
 7
    
    Include for offerings that have been
increased pursuant to Rule 462(b) under the Securities Act of 1933.8
    
    Include for offerings that have been
increased pursuant to Rule 462(b) under the Securities Act of 1933.9
    
    Include for offerings that have been
increased pursuant to Rule 462(b) under the Securities Act of 1933. Exhibit B-15




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provided however
         Exhibit B-16




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Exhibit B-17




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et seq
     Exhibit B-18




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Exhibit B-19




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Treasury Circular 230 Disclosure
   Exhibit B-20




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EXHIBIT A
 QUICKSILVER RESOURCES INC.
 Officers Certificate
 
 Underwriting Agreement Issuer General Partner Holdings Quicksilver Underwriters
 AK Opinion Letter
  Schedule 1 Applicable Agreements
 Schedule 2 Applicable Orders
  Exhibit B-21




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Face-Amount Certificate of the Installment Type
 Government Security
 Investment Securities
 Security Securities
 Exhibit B-22




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Schedule 3 Processing Partners Schedule 3
 Schedule 4 Pipeline Partners Schedule 4
 (Signature page follows)
 Exhibit B-23




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[Glenn Darden][President and Chief Executive Officer]Philip W. CookSenior Vice President and Chief Financial Officer
 Exhibit B-24




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Applicable Agreements
  1.
    
    Indenture Agreement for 1.875% Convertible Subordinated Debentures Due 2024, dated as of
November 1, 2004, between Quicksilver Resources Inc., as Issuer, and The Bank of New York, as
Trustee (as successor in interest to JPMorgan Chase Bank, National Association).
 2.
    
    Indenture, dated as of December 22, 2005, between Quicksilver Resources Inc. and The Bank of
New York, as Trustee (as successor in interest to JPMorgan Chase Bank, National Association).
 3.
    
    First Supplemental Indenture, dated as of March 16, 2006, among Quicksilver Resources Inc.,
the subsidiary guarantors named therein and The Bank of New York, as Trustee (as successor in
interest to JPMorgan Chase Bank, National Association).
 4.
    
    Third Supplemental Indenture, dated as of September 26, 2006, among Quicksilver Resources
Inc., the subsidiary guarantors named therein and The Bank of New York, as Trustee (as
successor in interest to JPMorgan Chase Bank, National Association).
 5.
    
    Amended and Restated Credit Agreement, dated as of February 9, 2007, among Quicksilver
Resources Inc. and the lenders identified therein.
 6.
    
    Amended and Restated Credit Agreement, dated as of February 9, 2007, among Quicksilver
Resources Canada Inc. and the lenders and/or agents identified therein.
 7.
    
    Credit Agreement dated as of August [___], 2007 by and among (i) Quicksilver Gas Services LP,
(ii) the Lenders party thereto, (iii) Bank of America, N.A., as Administrative Agent, (iv) BNP
Paribas, as Syndication Agent, and (v) JPMorgan Chase Bank, N.A., The Royal Bank of Scotland
plc and Fortis Capital Corp., as Co-Documentation Agents.
 8.
    
    Fifth Amended and Restated Cowtown Gas Facilities Gathering and Processing Agreement dated as
of August [___], 2007 by and among Quicksilver Resources Inc., Cowtown Pipeline Partners L.P.
and Cowtown Gas Processing Partners L.P.
 Exhibit B-25




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Applicable Orders
  Exhibit B-26




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Partnership Interest Transfer Ledger
 of
 Cowtown Gas Processing Partners L.P.
  Exhibit B-27




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Partnership Interest Transfer Ledger
 of
 Cowtown Pipeline Partners L.P.
  Exhibit B-28




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EXHIBIT C
 Form of Officers Certificate
 General Partner Partnership Company Company Underwriting Agreement
        Signature page follows
 Exhibit C-1




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Thomas F. DardenPresident and Chief Executive OfficerPhilip W. CookSenior Vice President  Chief Financial
Officer
 Exhibit C-2