SEVENTH AMENDMENT TO LOAN AGREEMENT

THIS SEVENTH AMENDMENT TO LOAN AGREEMENT (herein called this "Amendment") is made as of the 27th day of September, 2001 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.

WITNESSETH:

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; and

WHEREAS,
Borrower has informed Agent that Mountain Gas Resources, Inc. is investing in a limited liability company named Rendezvous Gas Services~ LLC., with Questar Gas Management
Company, and Borrower, Agent and Lenders desire to amend Schedule 4 to the Original Agreement to allow such Subsidiary's investment in such limited liability company,

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 following terms shall have the following meanings:



ARTICLE II.
Amendment and Consent

§
2.1. Schedule 4. Schedule 4 to the Original Loan Agreement is hereby amended in its entirety to read as set forth on Schedule 4 attached hereto.

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:



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 on the date hereof and as of the Effective
Date to each Lender that:



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 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 with 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 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.

IN
WITNESS WHEREOF, this Amendment is executed as of the date first above written.

| |  | WESTERN GAS RESOURCES, INC.                                                      
| |  | ---------------------------------------------------------------------------------
| |  | By: /s/ William J. Krysiak
Name: William J. Krysiak
Title: Vice President-Finance



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