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Exhibit 2.1
 EXECUTION COPY
 PURCHASE AGREEMENT
    Copano Energy, L.L.C.,
 Copano Energy/Rocky Mountains, L.L.C.,
  Cantera Resources Holdings LLC
   100% of the Membership Interests
  Cantera Natural Gas, LLC




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TABLE OF CONTENTS
 PageARTICLE 1DefinitionsSection 1.01. Definitions
    
    
    1Section 1.02. Other Definitional and Interpretative Provisions
    
    
    10ARTICLE 2Purchase and SaleSection 2.01. Purchase and Sale
    
    
    11Section 2.02. Closing
    
    
    11Section 2.03. Title Defects
    
    
    13Section 2.04. Closing Estimates
    
    
    15Section 2.05. Post-Closing Purchase Price Reconciliation
    
    
    15Section 2.06. Allocation of Purchase Price
    
    
    17ARTICLE 3Representations and Warranties of SellerSection 3.01. Existence and Power
    
    
    18Section 3.02. Seller Authorization
    
    
    18Section 3.03. Governmental Authorization
    
    
    19Section 3.04. Noncontravention
    
    
    19Section 3.05. Capitalization
    
    
    19Section 3.06. Ownership of Interests; Acquisition for Investment
    
    
    20Section 3.07. Subsidiaries
    
    
    21Section 3.08. Financial Statements
    
    
    22Section 3.09. Absence of Certain Changes
    
    
    23Section 3.10. Intercompany Accounts
    
    
    24Section 3.11. Material Contracts
    
    
    25Section 3.12. Litigation
    
    
    27Section 3.13. Compliance with Laws and Court Orders
    
    
    27Section 3.14. Properties
    
    
    27Section 3.15. Intellectual Property
    
    
    28Section 3.16. Insurance Coverage
    
    
    28Section 3.17. Finders Fees
    
    
    29Section 3.18. Employees
    
    
    29Section 3.19. Employee Benefit Plans
    
    
    29Section 3.20. Tax Matters
    
    
    31i




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PageSection 3.21. Environmental Matters
    
    
    32Section 3.22. Employment Matters
    
    
    32Section 3.23. Governmental Regulation
    
    
    33Section 3.24. Indebtedness
    
    
    33Section 3.25. Certain Business Relationships
    
    
    33Section 3.26. Non-Consent Payouts
    
    
    33Section 3.27. Inspections; No Other Representations
    
    
    33ARTICLE 4Representations and Warranties of Parent and BuyerSection 4.01. Existence and Power
    
    
    34Section 4.02. Authorization
    
    
    34Section 4.03. Governmental Authorization
    
    
    35Section 4.04. Noncontravention
    
    
    35Section 4.05. Capitalization
    
    
    35Section 4.06. Parent SEC Filings
    
    
    37Section 4.07. Offering
    
    
    38Section 4.08. Financing
    
    
    38Section 4.09. Purchase for Investment
    
    
    38Section 4.10. Litigation
    
    
    38Section 4.11. Finders Fees
    
    
    38Section 4.12. Inspections; No Other Representations
    
    
    39ARTICLE 5Covenants of SellerSection 5.01. Conduct of the Company
    
    
    39Section 5.02. Access to Information
    
    
    43Section 5.03. Notices of Certain Events
    
    
    44Section 5.04. Resignations; Employee Transfers
    
    
    45Section 5.05. Termination of Options
    
    
    45Section 5.06. Indemnification of Buyer
    
    
    45Section 5.07. Transfer of Retained Assets
    
    
    46Section 5.08. Financial Statements
    
    
    46Section 5.09. Related Party Agreements; Intercompany Balances
    
    
    47Section 5.10. Environmental Matters
    
    
    47Section 5.11. Confidentiality
    
    
    47Section 5.12. Non-Solicitation
    
    
    48ARTICLE 6Covenants of Parent and BuyerSection 6.01. Confidentiality
    
    
    48ii




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PageSection 6.02. Access
    
    
    48Section 6.03. Trademarks; Tradenames
    
    
    49Section 6.04. Waiver of Conflicts and Attorney-Client Privilege
    
    
    49Section 6.05. Marketing of Class D Units
    
    
    49ARTICLE 7Covenants of Parent, Buyer and SellerSection 7.01. Reasonable Best Efforts; Further Assurances
    
    
    50Section 7.02. Certain Filings
    
    
    51Section 7.03. Public Announcements
    
    
    51Section 7.04. WARN Act
    
    
    51Section 7.05. Transfer Taxes
    
    
    51Section 7.06. Transition Services
    
    
    51Section 7.07. Registration Rights Agreement; Voting and Lock-Up
Agreement; Transfer of Class D Units
    
    
    52Section 7.08. Partnership Information Returns
    
    
    52ARTICLE 8Employee BenefitsSection 8.01. Employees; Maintenance of Employee Benefits
    
    
    52ARTICLE 9Conditions to ClosingSection 9.01. Conditions to Obligations of Buyer and Seller
    
    
    55Section 9.02. Conditions to Obligation of Buyer
    
    
    56Section 9.03. Conditions to Obligation of Seller
    
    
    57ARTICLE 10TerminationSection 10.01. Grounds for Termination
    
    
    57Section 10.02. Effect of Termination
    
    
    57ARTICLE 11Tax MattersSection 11.01. Federal Income Tax Indemnity
    
    
    58Section 11.02. Federal Income Tax Contests
    
    
    58Section 11.03. Purchase Price Adjustments
    
    
    59iii




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PageARTICLE 12MiscellaneousSection 12.01. Survival of Representations, Warranties and Agreements
    
    
    59Section 12.02. Notices
    
    
    60Section 12.03. Amendments and Waivers
    
    
    61Section 12.04. Expenses
    
    
    61Section 12.05. Successors and Assigns
    
    
    61Section 12.06. Governing Law
    
    
    62Section 12.07. Jurisdiction
    
    
    62Section 12.08. WAIVER OF JURY TRIAL
    
    
    62Section 12.09. Counterparts; Effectiveness; Third Party Beneficiaries
    
    
    62Section 12.10. Guaranty
    
    
    63Section 12.11. Entire Agreement
    
    
    63Section 12.12. Severability
    
    
    63Section 12.13. Disclosure Schedules; Certain Representations and Warranties
Made to the Knowledge of Seller
    
    
    63Section 12.14. Antidilution
    
    
    64iv




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PURCHASE AGREEMENT
 Agreement Parent Buyer Seller
 W I T N E S S E T H :
 Interests Company
   Definitions
 Definitions
 Affiliate provided
 Balance Sheet Date




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Base Purchase Price
 Base Cash Purchase Price minus
 Bighorn
 Business Day
 Canyon
 Class C Units
 Class D Amendment
 Class D Units
 Closing Date
 Code
 Common Units
 Company Intellectual Property Rights
 Confidentiality Agreement
 Contract
 Credit Agreement
 2




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Current Assets provided however
 Current Liabilities provided however
 Easements
 Effective Time Adjustment Amount
 Effective Time Net Working Capital
 3




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Environmental Laws
 ERISA
 ERISA Affiliate
 Estimated Cash Purchase Price plus minus minus
 Estimated Purchase Price plus
 Excess Fort Union Indebtedness
 Exchange Act
 Fort Union
 Fort Union Credit Facility
 4




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GAAP
 Gathering Systems
 Governmental Authority
 Hazardous Materials
 HSR Act
 Indebtedness
 Intellectual Property Right
 Knowledge of Seller Sellers knowledge
 5




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LIBOR per annum
 Lien
 Material Adverse Effect provided
 Parent LLC Agreement
 Permitted Indebtedness
 6




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Permitted Liens
 Person
 Release
 Retained Assets
 SEC
 7




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Securities Act
 Specified Employee Liabilities
 Subsidiary
 Title Defect
 Title Defect Amount
 8




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Canyon Transition Services Agreement
  Term
    
    SectionAccounting Firm
    
    2.05Agreed-Upon Title Defect
    
    2.03Agreed-Upon Title Defect Amount
    
    2.03Agreement
    
    PreambleAllocation Statement
    
    2.06Applicable Percentage
    
    11.01Audit Firm
    
    5.08Audited Financial Statements
    
    3.08Buyer
    
    PreambleBuyer Confidential Information
    
    5.10Buyer DC Plans
    
    8.01Buyer Notice of Disagreement
    
    2.05Buyer Obligations
    
    12.10Canyon Employees
    
    3.18Closing
    
    2.01Closing Statement
    
    2.05Company
    
    RecitalsCompany 401(k) Plan
    
    8.01Company Confidential Information
    
    5.10Company Leases
    
    3.14Company Real Property
    
    3.14Company Securities
    
    3.05Current Representation
    
    6.04Damages
    
    5.05Delaware LLC Act
    
    4.05Effective Time
    
    2.02Employee Leasing Agreement
    
    7.06Employee Plans
    
    3.19Estimated Closing Statement
    
    2.04Estimated Net Working Capital Amount
    
    2.04Federal Income Tax
    
    11.01Final Effective Time Adjustment Amount
    
    2.05Financial Statements
    
    3.08Financing
    
    7.01Interests
    
    Recitals
 9




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Term
    
    SectionInterim Interest
    
    2.02Interim Financial Statements
    
    3.08Lock-Up Expiration Date
    
    6.05Notice of Disagreement
    
    2.03Option Plan
    
    3.05Options
    
    3.05Owned Real Property
    
    3.14Parent
    
    PreambleParent SEC Documents
    
    4.06Partnerships
    
    3.20Post-Closing Representation
    
    6.04Purchase Price
    
    2.01Registration Rights Agreement
    
    7.07Retained Employees
    
    8.01Returns
    
    3.20Seller
    
    PreambleShared Services Employees
    
    7.06Subsidiary Securities
    
    3.07Title Defect Arbitrator
    
    2.03Title Defect Determination Date
    
    2.03Title Defect Notice
    
    2.03Tax
    
    3.20Tax Allocation Referee
    
    2.06Taxing Authority
    
    3.20Transferred Employees
    
    8.01Voting and Lock-Up Agreement
    
    7.07WARN Act
    
    7.04
 . Other Definitional and Interpretative Provisions.
 10




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Purchase and Sale
 Purchase and Sale Purchase Price plus minus plus per annum plus per annum Interim Interest
 Closing Closing provided Effective Time
 11




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plus
 provided
     12




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. Title Defects. Title Defect Notice
 Notice of Disagreement
 Title Defect Arbitrator
 13




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Agreed-Upon Title Defect Title Defect Determination Date Agreed-Upon Title Defect Amount provided however
  14




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Title Defect
 . Closing Estimates Estimated Closing Statement Estimated Net
Working Capital Amount
 . Post-Closing Purchase Price Reconciliation. Closing Statement
  15




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plus per annum plus per annum
 Buyer
Notice of Disagreement Accounting Firm
 16




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Final Effective Time Adjustment Amount
   . Allocation of Purchase Price. Allocation Statement
 17




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Tax Allocation Referee
 Representations and Warranties of Seller
  Existence and Power
 Seller Authorization
 18




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Governmental Authorization
 Noncontravention
 Capitalization Options Option Plan
 19




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Company Securities
  Ownership of Interests; Acquisition for Investment
  20




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Subsidiaries
  21




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Subsidiary
Securities
   Financial Statements Financial Statements Audited Financial Statements Interim Financial Statements
 22




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Absence of Certain Changes
   23




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Intercompany Accounts
 24




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Material Contracts
        25




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Material Contracts
 26




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Litigation
 Compliance with Laws and Court Orders
 . Properties Owned Real Property Company
Leases Company Real Property
   27




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Intellectual Property
   Insurance Coverage
 28




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Finders Fees
 . Employees. Canyon Employees
 Employee Benefit Plans Employee Plans
 29




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30




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Tax Matters. Returns Partnerships Tax
 31




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Taxing Authority
 . Environmental Matters.
     . Employment Matters
  32




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. Governmental Regulation.
 . Indebtedness.
 . Certain Business Relationships
 . Non-Consent Payouts
 Inspections; No Other Representations
 33




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Representations and Warranties of Parent and Buyer
  Existence and Power
 Authorization
 34




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Governmental Authorization
 Noncontravention
 Capitalization. Delaware LLC Act
  35




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36




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Parent SEC Filings Parent SEC Documents Parent
Financial Statements
 37




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Offering
 Financing
 Purchase for Investment
 Litigation
 Finders Fees
 38




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Inspections; No Other Representations
 Covenants of Seller
  Conduct of the Company
 39




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provided
    40




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41




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42




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Access to Information
 43




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provided
 Notices of Certain Events
 provided however
 44




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Resignations; Employee Transfers
 . Termination of Options
 . Indemnification of Buyer Damages provided
 45




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. Transfer of Retained Assets
 Financial Statements Audit Firm
  46




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Related Party Agreements; Intercompany Balances
 Environmental Matters
 Confidentiality Company Confidential Information Buyer Confidential
Information
 47




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Non-Solicitation provided
 Covenants of Parent and Buyer
  Confidentiality
 Access
 48




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provided
 Trademarks; Tradenames
 . Waiver of Conflicts and Attorney-Client Privilege Current Representation Post-Closing
Representation
 Marketing of Class D Units Lock-Up Expiration Date
 49




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Covenants of Parent, Buyer and Seller
  Reasonable Best Efforts; Further Assurances
  Financing provided, however
 50




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Certain Filings
 Public Announcements
 . WARN Act. WARN Act
 . Transfer Taxes
 Transition Services Employee Leasing Agreement Shared Services Employees
 51




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Registration Rights Agreement; Voting and Lock-Up Agreement; Transfer of
Class D Units Registration Rights
Agreement Voting and Lock-Up Agreement
  . Partnership Information Returns
 Employee Benefits
 . Employees; Maintenance of Employee Benefits. Retained Employees Transferred Employees
 provided however
  52




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Company 401(k) Plan
 Buyer DC Plans
    53




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provided
   54




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Conditions to Closing
 Conditions to Obligations of Buyer and Seller
    55




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Conditions to Obligation of Buyer
       56




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Conditions to Obligation of Seller
   Termination
 Grounds for Termination
  provided
   Effect of Termination provided
 57




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Tax Matters
 Federal Income Tax Indemnity provided Federal Income Tax Applicable Percentage
 Federal Income Tax Contests
 58




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Purchase Price Adjustments
 Miscellaneous
 Survival of Representations, Warranties and Agreements.
 59




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. Notices.
  
  
  
 60




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th
  
  Amendments and Waivers
  Expenses
 Successors and Assigns provided
 61




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provided
 Governing Law
 Jurisdiction
 WAIVER OF JURY TRIAL
 Counterparts; Effectiveness; Third Party Beneficiaries
 62




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Guaranty Buyer Obligations
 Entire Agreement
 Severability.
 Disclosure Schedules; Certain Representations and Warranties Made to the
Knowledge of Seller
 63




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Antidilution
 64




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COPANO ENERGY/ROCKYMOUNTAINS, L.L.C.By:
    
    /s/ John R. EckelName:
    
    John R. Eckel, Jr.Title:
    
    Chairman and CEOCOPANO ENERGY, L.L.C.By:
    
    /s/ John R. EckelName:
    
    John R. Eckel, Jr.Title:
    
    Chairman and CEOCANTERA RESOURCESHOLDINGS, LLCBy:
    
    /s/
Greg W. SalesName:
    
    Greg W. SalesTitle:
    
    Authorized Signatory