Exhibit 99.1

FOR IMMEDIATE RELEASE

Earthstone Energy, Inc. Reports Fourth Quarter and Full Year 2014 Results

Houston, Texas, March 27, 2015 – Earthstone Energy, Inc. (NYSE MKT: ESTE) (“Earthstone” or the “Company”), today announced financial and operating results for the three and twelve month periods ended December 31, 2014.

Recent Transactions – Basis of Reporting

On December 19, 2014, the Company completed a strategic combination with Oak Valley Resources, LLC (“Oak Valley”), which resulted in a change of control, and concurrently acquired additional interests in an existing Eagle Ford development project located in Fayette and Gonzales Counties, Texas. The Company’s property portfolio now includes activities in the Eagle Ford trend of south Texas and in the Williston Basin, including both North Dakota and Montana. The strategic combination has been accounted for as a reverse acquisition whereby the subsidiaries of Oak Valley are considered the acquirer for accounting and reporting purposes. Accordingly, all historical information provided in this release and in Earthstone’s 2014 Annual Report on Form 10-K and other filings with the Securities and Exchange Commission is that of Oak Valley, with the Earthstone and the Eagle Ford transactions treated as acquisitions on December 19, 2014. Additionally, the Company adopted Oak Valley’s fiscal year-end of December 31.

Full Year 2014 Highlights Compared to Full Year 2013

Fourth Quarter 2014 Highlights Compared to Fourth Quarter 2013

2014 Year-End Proved Reserves

SEC rules require that the reserve calculations utilize the unweighted average price on the first day of the month for the prior twelve-month period.  Oil, natural gas, and natural gas liquids prices used for our 2014 year-end reserve report, prior to adjusting for quality and basis differentials, were $94.99 per barrel, $4.309 per MMBtu (million British Thermal units), and $30.19 per barrel,

respectively. The following table indicates estimated proved reserves by category as of December 31, 2014.

Note: PV-10 is a non-GAAP financial measure. See “Reconciliation of Non-GAAP Financial Measures” section below.

Selected Financial Data

Management Comments

Frank A. Lodzinski, President and Chief Executive Officer of Earthstone Energy, Inc., commented, “Our senior management team has re-entered the public markets for the fourth time with our December 2014 strategic combination with Earthstone, and despite the current price environment, we look forward to achieving profitable growth. We are pleased with our accomplishments to-date.   In just two short years since we acquired and recapitalized Oak Valley, we have assembled a significant reserve and production position. We achieved this growth, as we have in prior public entities, through a combination of development drilling, asset acquisitions and corporate M&A activities. Our goals are

to continue this significant progress with continued development of our current assets, expansion of additional acreage positions, and acquisitions. In addition, we will continue to pursue Corporate M&A opportunities. We intend to pursue such opportunities aggressively but prudently.”

About Earthstone Energy, Inc.

Earthstone Energy, Inc. is a growth-oriented independent oil and gas exploration and production company engaged in the development and acquisition of oil and gas reserves through an active and diversified program that includes the acquisition, drilling and development of undeveloped leases, and purchases of reserves and exploration activities, with its current primary assets located in the Eagle Ford trend of south Texas and in the Williston Basin of North Dakota and Montana. Earthstone is traded on NYSE MKT under the symbol “ESTE.” Information on Earthstone can be found at www.earthstoneenergy.com. Our corporate headquarters is located in The Woodlands, Texas. We also have an operating office in Denver, Colorado.

FORWARD-LOOKING STATEMENTS

This release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Statements that are not strictly historical statements constitute forward-looking statements and may often, but not always, be identified by the use of such words such as “expects,” “believes,” “intends,” “anticipates,” “plans,” “estimates,” “potential,” “possible,” or “probable” or statements that certain actions, events or results “may,” “will,” “should,” or “could” be taken, occur or be achieved. The forward-looking statements include statements about future operations, expansion of production and development acreage, increased cash flow, earnings and assets and access to capital. Forward-looking statements are based on current expectations and assumptions and analyses made by Earthstone and its management in light of experience and perception of historical trends, current conditions and expected future developments, as well as other factors appropriate under the circumstances. However, whether actual results and developments will conform to expectations is subject to a number of material risks and uncertainties, including but not limited to: the risks of the oil and gas industry (for example, the recent rapid, significant decline in oil prices and operational risks in exploring for, developing and producing crude oil and natural gas; risks and uncertainties involving geology of oil and gas deposits); the uncertainty of reserve estimates; the uncertainty of estimates and projections relating to future oil and gas prices, production, costs and expenses; potential delays or changes in plans with respect to exploration or development projects or capital expenditures; health, safety and environmental risks and risks related to weather; inability of management to execute its plans to meet its goals; unavailability of gathering systems, pipelines and processing facilities; and the possibility that government policies may change. Earthstone’s annual report on Form 10-K for the year ended December 31, 2014, recent current reports on Form 8-K, and other SEC filings discuss some of the important risk factors identified that may affect Earthstone’s business, results of operations, and financial condition. Earthstone undertakes no obligation to revise or update publicly any forward-looking statements except as required by law.

Contact:

Neil K. Cohen

Vice President, Finance, and Treasurer

Earthstone Energy, Inc.

1400 Woodloch Forest Drive, Suite 300

The Woodlands, TX 77380

281-298-4246

EARTHSTONE ENERGY, INC.

CONSOLIDATED BALANCE SHEETS

(In thousands, except share and per share amounts)

EARTHSTONE ENERGY, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except share and per share amounts)

EARTHSTONE ENERGY, INC.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

Earthstone Energy, Inc.
Reconciliation of Non-GAAP Financial Measures
Unaudited

I. PV-10

PV-10 is derived from the Standardized Measure of discounted future net cash flows, which is the most directly comparable GAAP financial measure.  PV-10 is a computation of the Standardized Measure on a pre-tax basis.  PV-10 is equal to the Standardized Measure at the applicable date, before deducting future income taxes, discounted at 10%.  We believe that the presentation of PV-10 is relevant and useful to investors because it presents the discounted future net cash flows attributable to our estimated net proved reserves prior to taking into account future corporate income taxes, and it is a useful measure for evaluating the relative monetary significance of our oil and natural gas properties.  Further, investors may utilize the measure as a basis for comparison of the relative size and value of our reserves to other companies.  We use this measure when assessing the potential return on investment related to our oil and natural gas properties.  PV-10, however, is not a substitute for the Standardized Measure.  Our PV-10 measure and the Standardized Measure do not purport to present the fair value of our oil and natural gas reserves.

The following table provides a reconciliation of PV-10 of our proved properties to the Standardized Measure (in thousands):

II. Adjusted EBITDAX

Adjusted EBITDAX is used as a supplemental financial measure by our management and by external users of our financial statements, such as investors, commercial banks and others, to assess our operating performance compared to that of other companies in our industry, without regard to financing methods, capital structure or historical costs basis.  It is also used to assess our ability to incur and service debt and fund capital expenditures.  We define “Adjusted EBITDAX” as net income (loss) plus (1) (gain) loss on sale of assets; (2) accretion; (3) impairment expense; (4) depletion, depreciation, and amortization; (5) exploration expense; (6) interest expense; (7) interest income; (8) unrealized (gain) loss on derivatives; and (9) income tax expense (benefit).

Our Adjusted EBITDAX should not be considered an alternative to net income (loss), operating income (loss), cash flow provided by (used in) operating activities or any other measure of financial performance or liquidity presented in accordance with GAAP.  Our Adjusted EBITDAX may not be comparable to similarly titled measures of another company because all companies may not calculate Adjusted EBITDAX in the same manner.

The following table provides a reconciliation of net income to Adjusted EBITDAX for the periods indicated: