Gastar Exploration (GST) 10-K/A 2012 FY Annual report (amended)

Exhibit 31.3

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER

PURSUANT TO 15 U.S.C. SECTION 7241, AS ADOPTEDPURSUANT TO SECTION 302 OF THESARBANES-OXLEY ACT OF 2002

I, J. Russell Porter, certify that:

1. I have reviewed this annual report on Form 10-K/A of Gastar Exploration USA, Inc.; and

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report.

Date: April 29, 2013

/s/ J. RUSSELL PORTER

J. Russell Porter

President