May 3, 2010
Earthstone Energy, Inc.
633 17 th Street, Suite 1645
Denver, Colorado 80202
At your request, Ryder Scott Company (Ryder Scott) has prepared an estimate of the proved reserves,
future production, and income attributable to certain leasehold and royalty interests of Earthstone Energy, Inc.
(Earthstone) as of March 31, 2010. The subject properties are located in the states of Colorado, Louisiana,
Montana, North Dakota and Texas. The reserves and income data were estimated based on the definitions and
disclosure guidelines of the United States Securities and Exchange Commission (SEC) contained in Title 17,
Code of Federal Regulations, Modernization of Oil and Gas Reporting, Final Rule released January 14, 2009 in
the Federal Register (SEC regulations). Our third party study, completed on May 3, 2010 and presented herein,
was prepared for public disclosure by Earthstone in filings made with the SEC in accordance with the disclosure
requirements set forth in the SEC regulations . The results of our third party study, completed on May 3, 2010,
are presented herein. The properties reviewed by Ryder Scott represent approximately 91 percent of the total
net proved liquid hydrocarbon reserves and 94 percent of the total net proved gas reserves of Earthstone.
The estimated reserves and future net income amounts presented in this report, as of March 31, 2010 are
related to hydrocarbon prices. The hydrocarbon prices used in the preparation of this report are based on the
average prices during the 12-month period prior to the ending date of the period covered in this report,
determined as unweighted arithmetic averages of the prices in effect on the first-day-of-the-month for each month
within such period, unless prices were defined by contractual arrangements as required by the SEC
regulations. Actual future prices may vary significantly from the prices required by SEC regulations; therefore,
volumes of reserves actually recovered and the