Exhibit 10.16  SECOND AMENDMENT TO LOAN AGREEMENT  THIS SECOND
AMENDMENT TO LOAN AGREEMENT (herein called this Amendment) is made as of the
22nd day of November, 1999 by and among Western Gas Resources, Inc.
(Borrower), and Bank of America, N.A. (Agent), and the Lenders under the
Loan Agreement referred to below.  W I T N E S S E T H:  WHEREAS,
Borrower, Agent, and Lenders have entered into that certain Loan Agreement
dated as of April 29, 1999 (as amended, restated, or supplemented to the date
hereof, the Original Agreement), for the purposes and consideration therein
expressed, pursuant to which Lenders made and became obligated to make loans to
Borrower as therein provided;  WHEREAS, Borrower, Agent, and
Lenders desire to amend the Original Agreement for the purposes described
herein;  NOW,
THEREFORE, in consideration of the premises and the mutual covenants and
agreements contained herein and in the Original Agreement, in consideration of
the loans which may hereafter be made by Lenders to Borrower, and for other
good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the parties hereto do hereby agree as follows:  ARTICLE I.  Definitions and References  §1.1.Defined
Terms.Unless the context
otherwise requires or unless otherwise expressly defined herein, the terms
defined in the Original Agreement shall have the same meanings whenever used in
this Amendment. As used herein, the term Loan Agreement means the Original
Agreement as amended by this Amendment.  ARTICLE II.  Amendment  §2.1.Definitions.The
definition of Funded Debt in Section 1.1 of the Loan Agreement is hereby
amended in its entirety to read as follows:  Funded Debt means (without duplication) the aggregate of the
following Debt of Borrower and its Subsidiaries, after elimination of
intercompany items and other Consolidation in accordance with GAAP: (a) Debt
(including the Obligations) for  
   borrowed
money, regardless of maturity, (b) Debt constituting an obligation to pay the
deferred purchase price of property, (c) Debt evidenced by a bond, debenture,
note or similar instrument, (d) Debt which is due and payable at the time in
question, with respect to letters of credit or reimbursement agreements
therefor, and (e) obligations payable under leases whether or not such payments
are capitalized in accordance with GAAP, but only the amount thereof which at
the time in question exceeds $35,000,000, in the aggregate, excluding
obligations arising under oil and gas leases, real estate leases for office
space used by Borrower, and leases for vehicles, office equipment and data
processing equipment.  §2.2.Debt.
Section 6.2(a)(iii) of the Original Agreement is hereby amended to read in its
entirety as follows:  (iii)obligations
under leases, whether capital leases or operating leases, entered into in the
ordinary course of business in arms-length transactions at competitive market
rates under competitive terms and conditions considering all aspects thereof,
provided that the obligations payable over the remaining lives of any such
leases do not in the aggregate exceed $50,000,000, and in addition, obligations
under oil and gas leases, real estate leases for office space used by Borrower,
and leases for vehicles, office equipment and data processing equipment;  ARTICLE III.  Conditions of Effectiveness  §3.1.Effective
Date. This Amendment shall become effective as of the date first above
written when, and only when, Agent shall have received all of the
following:  (a)This
Amendment, duly authorized, executed and delivered by Borrower and Majority
Lenders, and in form and substance satisfactory to Agent.  (b)A
certificate of a duly authorized officer of Borrower to the effect that all of
the representations and warranties set forth in Article IV hereof are true and
correct at and as of the time of such effectiveness.  (c)Payment
of all fees and expenses owing to Agent and Lenders in connection with the Loan
Agreement and payment of fees and disbursements of Thompson & Knight L.L.P.
relating to this Amendment and the Loan Agreement as provided in the Loan
Agreement.  2 
   ARTICLE IV.  Representations and Warranties  §4.1.Representations
and Warranties of Borrower. In order to induce each Lender to enter into
this Amendment, Borrower represents and warrants to each Lender that:  (a)The
representations and warranties contained in Article V of the Original Agreement
are true and correct at and as of the time of the effectiveness hereof (except
as such representations and warranties have been modified by the transactions
contemplated herein).  (b)Borrower
is duly authorized to execute and deliver this Amendment and Borrower is and
will continue to be duly authorized to borrow monies and to perform its
obligations under the Loan Agreement. Borrower has duly taken all corporate
action necessary to authorize the execution and delivery of this Amendment.  (c)The
execution and delivery by Borrower of this Amendment, the performance of its
obligations hereunder and the consummation of the transactions contemplated
hereby do not and will not conflict with any provision of law, statute, rule or
regulation or of the certificate of incorporation and bylaws of Borrower or of
any material agreement, judgment, license, order or permit applicable to or
binding upon Borrower or result in the creation of any lien, charge or
encumbrance upon any assets or properties of Borrower. Except for those which
have been obtained, no consent, approval, authorization or order of any court
or governmental authority or third party is required in connection with the
execution and delivery by Borrower of this Amendment.  (d)When
duly executed and delivered, this Amendment and the Loan Agreement will be a
legal and binding obligation of Borrower enforceable against Borrower in
accordance with its terms, except as limited by bankruptcy, insolvency or
similar laws of general application relating to the enforcement of creditors
rights and by equitable principles of general application.  (e)The
unaudited Consolidated quarterly financial statements of Borrower dated as of
June 30, 1999 fairly present the Consolidated financial position at such date
of Borrower and the Consolidated statement of operations and the changes in
Consolidated financial position for the periods ending on such date for
Borrower. Copies of such financial statements have heretofore been delivered to
Agent. Since June 30, 1999, no material adverse change has occurred in the
financial condition or business or in the Consolidated financial condition or
business of Borrower.  3 
   ARTICLE V.  Miscellaneous  §5.1.Ratification
of Agreements. The Original Agreement as hereby amended is hereby ratified
and confirmed in all respects. Any reference to the Loan Agreement in any Loan
Document shall be deemed to be a reference to the Original Agreement as hereby
amended. The Loan Documents, as they may be amended or affected by this
Amendment, are hereby ratified and confirmed in all respects. The execution,
delivery and effectiveness of this Amendment shall not, except as expressly
provided herein, operate as a waiver of any right, power or remedy of Lenders
under the Loan Agreement, the Notes, or any other Loan Document nor constitute
a waiver of any provision of the Loan Agreement, the Notes, or any other Loan
Document.  §5.2.Survival
of Agreements. All representations, warranties, covenants and agreements of
Borrower herein shall survive the execution and delivery of this Amendment and
the performance hereof, including without limitation the making or granting of
the Loans, and shall further survive until all of the Obligations are paid in
full. All statements and agreements contained in any certificate or instrument
delivered by Borrower hereunder or under the Loan Agreement to any Lender shall
be deemed to constitute representations and warranties by, and/or agreements
and covenants of, Borrower under this Amendment and under the Loan Agreement.  §5.3.Loan
Documents. This Amendment is a Loan Document, and all provisions in the
Loan Agreement pertaining to Loan Documents apply hereto.  §5.4.Governing
Law. This Amendment shall be governed by and construed in accordance the
laws of the State of Texas and any applicable laws of the United States of
America in all respects, including construction, validity and performance.  §5.5.Counterparts.
This Amendment may be separately executed in counterparts and by the different
parties hereto in separate counterparts, each of which when so executed shall
be deemed to constitute one and the same Amendment.  THIS AMENDMENT AND THE OTHER LOAN DOCUMENTS
REPRESENT THE FINAL AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED
BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OF THE
PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS OF THE PARTIES.  4 
   IN WITNESS
WHEREOF, this Amendment is executed as of the date first above written.  WESTERN GAS
  RESOURCES, INC.By:
  /s/ William KrysiakName: William KrysiakTitle: VPFinance  
   BANK OF
  AMERICA, N.A., as Agent and LenderBy:
  /s/ Tracey S. BarclayName: Tracey S. BarclayTitle:  
   SOCIETE
  GENERALE SOUTHWEST AGENCY,
  a LenderBy:
  /s/ Paul E. CornellName: Paul E. CornellTitle: Managing Director  
   ABN AMRO
  BANK N.V., a LenderBy:
  /s/ Robert J. CunninghamName:
  Robert J. CunninghamTitle:
  Group Vice PresidentBy:
  /s/ Jamie A. ConnName:
  Jamie A. ConnTitle:
  Vice President  
   BANKBOSTON,
  N.A., a LenderBy:
  /s/ Bryon E. CailName: Bryon E. CailTitle: Loan Officer  
   UNION BANK
  OF CALIFORNIA, N.A., a LenderBy:
  /s/ Gary ShekerjianName:
  Gary ShekerjianTitle:
  Assistant Vice PresidentBy:
  /s/ Damien MelburgerName:
  Damien MelburgerTitle:
  Senior Vice President  
   BANK ONE, NA, a LenderBy:
  /s/ Dixon P. SchultzName: Dixon P. SchultzTitle: First Vice President  
   U.S. BANK
  NATIONAL ASSOCIATION,
  a LenderBy:
  /s/ Caroline M McClurgName: Caroline M McClurgTitle: Vice President  
   CREDIT
  LYONNAIS, a LenderBy:
  /s/ Philippe SoustraName: Philippe SoustraTitle: Senior Vice President  
   CONSENT AND AGREEMENT  Each of the
undersigned hereby (i) consents to the provisions of this Amendment and the
transactions contemplated herein, and (ii) ratifies and confirms its respective
Guaranty dated as of April 29, 1999 made by it in favor of Agent for the
benefit of each Lender, and agrees that its obligations and covenants
thereunder are unimpaired hereby and shall remain in full force and effect.  MIGC, INC.WESTERN GAS
  RESOURCES TEXAS, INC.MOUNTAIN GAS
  RESOURCES, INC.WESTERN GAS
  RESOURCES-OKLAHOMA,
  INC.LANCE OIL
  & GAS COMPANY, INC.PINNACLE GAS
  TREATING, INC.WESTERN GAS
  WYOMING, L.L.C.  By:
  /s/ John C. WalterName: John C. WalterTitle: Executive Vice President  CONSENT AND AGREEMENT  The
undersigned hereby (i) consents to the provisions of this Amendment and the
transactions contemplated herein, and (ii) ratifies and confirms its Guaranty
dated as of October 14, 1999 made by it in favor of Agent for the benefit of
each Lender, and agrees that its obligations and covenants thereunder are unimpaired
hereby and shall remain in full force and effect.  MGTC, INC.By:
  /s/ John C. WalterName: John C. WalterTitle: Executive Vice President