AEP INDEMNIFICATION AGREEMENT

Exhibit 10.1

Execution Version

AEP INDEMNIFICATION AGREEMENT

This AEP INDEMNIFICATION AGREEMENT (this “Agreement”) is made and entered into as of March 1, 2013, by and between Anadarko E&P Onshore LLC, a Delaware limited liability company (“Indemnitor”) and Western Gas Holdings, LLC, a Delaware limited liability company (“Indemnitee”).

WITNESSETH:

WHEREAS, Western Gas Partners, LP, a Delaware limited partnership (“Borrower”), has entered into the Amended and Restated Revolving Credit Agreement (“Restated Credit Agreement”) dated as of March 24, 2011, by and among the Borrower, Wells Fargo Bank, National Association, individually and as Administrative Agent, DnB NOR Bank ASA, as Syndication Agent, Bank of Montreal, Comerica Bank and The Bank of Tokyo-Mitsubishi UFJ, Ltd., as Documentation Agents, and the Lenders party thereto;

WHEREAS, Revolving Loans under the Restated Credit Agreement have been or will be made in connection with Borrower’s acquisition of certain midstream assets in (i) AMI Area A of Northern Pennsylvania (“Area A Loan”) and (ii) AMI Area B of Northern Pennsylvania (“Area B Loan”);

WHEREAS, Indemnitor owns 100% of the limited liability company interests of Anadarko Marcellus Midstream, L.L.C. (“AMM), which is a disregarded entity for federal income tax purposes;

WHEREAS, AMM is a limited partner of Borrower;

WHEREAS, Indemnitor, through a distribution received from AMM, has received proceeds of borrowings made pursuant to the Area A Loan;

WHEREAS, Indemnitee is the general partner of Borrower;

WHEREAS, Indemnitee may, in such capacity, incur certain liabilities in connection with the Restated Credit Agreement, including, without limitation, the obligation to pay the Principal Amount of the Area A Loan and the Area B Loan;

WHEREAS, Borrower entered into the Indenture (“Indenture”) dated as of May 18, 2011, by and among Borrower and Wells Fargo Bank, National Association, as Trustee;

WHEREAS, under the Indenture, Borrower may establish a new series of Debt Securities (as defined in the Indenture) at any time in accordance with the provisions of the Indenture;

WHEREAS, the proceeds of Debt Securities under the Indenture may be used to refinance outstanding Revolving Loans, including the Area A Loan and the Area B Loan, and for other general corporate purposes; and

WHEREAS, the Indemnitor and Indemnitee wish to enter into an agreement to provide for the indemnification by Indemnitor of Indemnitee for future claims that might be made against

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Indemnitee with respect to the Area A Loan and the Area B Loan or any indebtedness incurred by Borrower to refinance Indebtedness incurred pursuant to the Area A Loan and the Area B Loan using Debt Securities.

NOW, THEREFORE, in consideration of the above premises and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto agree as follows:

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determines that the expense anticipated to be incurred by Indemnitee in pursuing such claim against Borrower with respect to collection of the amount of the Lender Claim would exceed the anticipated recovery from Borrower with respect to such claim.

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Western Gas Holdings, LLC

Attn: President

1201 Lake Robbins Drive

The Woodlands, Texas 77380

Anadarko E&P Onshore LLC

Attn: President

1201 Lake Robbins Drive

The Woodlands, Texas 77380

    or to any other address as may have been furnished by Indemnitee or Indemnitor to the other party.

[Signature Page Follows]

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IN WITNESS WHEREOF, the parties hereto have executed and delivered this Agreement as of the date first written above.