EXHIBIT A
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VIA FACSIMILE & U.S. MAIL

August 15, 2005

Mr. Peter A. Dea
Chief Executive Officer, President
Western Gas Resources, Inc.
1099 18th Street, Suite 1200
Denver, CO 80202

Dear Mr. Dea:

Thank you for meeting with us in Denver last week. We are impressed with the
progress that Western Gas Resources, Inc. (the "Company") has made in obtaining
permits in the Powder River Basin and elsewhere which will enable it to reach
and exceed its production growth objectives. We were also pleased to be informed
of the potential for increased throughput volumes in the Company's Oklahoma
gathering assets. These accomplishments coupled with historically high gas
prices have caused us to reassess our valuation and price target for the
Company. Our own estimates of the Company's intrinsic value are well in excess
of both the current trading levels of approximately $42.50 and "street"
valuations such as that of UBS at $54.00 per share.

Accordingly, we recommend that the Company immediately utilize its significant
borrowing capacity to initiate a share repurchase program of $300--$500 million
representing 10 - 15% of the outstanding shares. In addition, we urge the
Company to use a portion of future operating cash flow to purchase shares. We
vehemently disagree with the Board's view that the Company should wait until the
"cash is in the bank" before pursuing such a course of action as we believe
there is a window of opportunity to buy back shares "on the cheap" before the
market comes to appreciate the impact of the current natural gas strip on future
cash flow. Such debt financing can be easily financed with current cash flow,
and forward prices can be locked in by hedging the natural gas strip or
employing a volumetric production payment ("VPP") transaction. We have already
discussed the Company's borrowing capacity with a global investment bank which
has confirmed that such a sum would be easy to finance.

We still believe that shareholders would be well served by separating the
Company's midstream gathering assets from its resource intense E&P business, but
now recommend that such a transaction should be preceded by a significant share
repurchase. Furthermore, we also deem that certain tax benefits would accrue to
the MLP entity by incurring debt at this time and that anticipated volumetric
growth in the Company's gathering businesses would lead to a higher valuation at
the time of the transaction.

I also have excellent news which I would like to share with you and the Board:
After significant reflection regarding the time commitments and constraints that
such a




responsibility would entail, I have decided to volunteer to serve on the
Company's Board of Directors, filling the seat recently vacated following the
retirement of Ward Sauvage. In this way, I will be able to personally and
directly be involved in the Company's initiatives to create and build
shareholder value. Third Point LLC is now the Company's largest shareholder,
owning 6,450,000 shares or approximately 8.6% of the outstanding shares.

I would look forward to serving alongside a respected Board of Directors, many
of whose members' expertise span many decades of industry experience and
insight. I believe my high regard for and intense focus on shareholder value
creation would be complementary to the operational and industrial backgrounds of
the current Directors.



Sincerely,

/s/ Daniel S. Loeb

Daniel S. Loeb