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Gastar Exploration Inc. (NYSE MKT: GST) (“Gastar”) today provided updated production data from its Deep River 30-1H well, its first operated test of the STACK formation Meramec Shale play in Kingfisher County, Oklahoma.  The Deep River 30-1H produced at a gross post IP 30-day average sales rate of 956 barrels of oil equivalent (“Boe”) per day (68% oil).  The well commenced flow back in late October 2015 and in December 2015, produced a peak 24-hour rate of 1,094 Boe per day (71% oil).  Gastar’s independent reservoir engineer has estimated the ultimate recovery (“EUR”) for the Deep River 30-1H well to be 705 MBoe as of December 31, 2015, with crude oil comprising 50% on a wet gas basis.  Gastar has a 100% working (80% net revenue) interest in the well.  The Deep River Meramec test well moved the productive outline of the Meramec play further northeast than previously defined.

As a result of the successful Deep River 30-1H well, the Company intends to spud its second Meramec well, the Holiday Road, also located in Kingfisher County, in February 2016. The Holiday Road well will be located in Section 2 18N, 6W approximately four miles north and three miles east of the Deep River 30-1H well.

J. Russell Porter, Gastar’s President and Chief Executive Officer, commented, “We continue to be pleased with the productivity of the Deep River Meramec test well and are very pleased to announce that the EUR estimate is 40% above the high-end of our pre-drill estimates.  We plan to continue to delineate our acreage to de-risk our Meramec position and are confident that this play can generate acceptable returns even with today’s commodity prices.”

About Gastar Exploration

Gastar Exploration Inc. is an independent energy company engaged in the exploration, development and production of oil, condensate, natural gas and natural gas liquids in the United States. Gastar’s principal business activities include the identification, acquisition, and subsequent exploration and development of oil and natural gas properties with an emphasis on unconventional reserves, such as shale resource plays. In Oklahoma, Gastar is developing the primarily oil-bearing reservoirs of the Hunton Limestone horizontal play and expects to test other prospective formations on the same acreage, including the Meramec Shale and the Woodford Shale, which industry refers to as the STACK Play. In West Virginia, Gastar has developed liquids-rich natural gas in the Marcellus Shale and has drilled and completed its first two successful dry gas Utica Shale/Point Pleasant wells on its acreage.  Gastar has engaged Tudor, Pickering, Holt & Co. to market its Marcellus Shale and Utica Shale/Point Pleasant assets in West Virginia.  For more information, visit Gastar’s website