X0306 4 2016-01-30 0 0001431372 Gastar Exploration Inc. GST 0001348372 Porter J Russell 1331 LAMAR, SUITE 650 HOUSTON TX 77010 1 1 0 0 Chief Executive Officer & Pres Common Stock 2016-01-30 4 A 0 404412 0.00 A 2287937 D Common Stock 2016-01-30 4 F 0 82354 1.19 D 2205583 D Common Stock 2016-01-30 4 M 0 254654 0.00 A 2460237 D Common Stock 2016-01-30 4 F 0 70867 1.19 D 2389370 D Common Stock 150000 I Trust 2013 Performance Based Units 0.00 2016-01-30 4 M 0 127327 0.00 D 2016-01-30 Common Stock 127327 0 D 2014 Performance Based Units 0.00 2016-01-30 4 J 0 38793 0.00 D 2017-01-30 Common Stock 38793 38793 D 2015 Performance Based Units 0.00 2018-01-30 Common Stock 286458 286458 D 2016 Performance Based Units 0.00 2016-01-30 4 A 0 404412 0.00 A 2019-01-30 Common Stock 404412 404412 D The reported shares were acquired pursuant to a restricted share grant and will vest in three equal annual installments beginning on January 30, 2017. Includes 631,479 shares acquired on various dates pursuant to previously reported restricted share grants that will vest subject to previously disclosed vesting schedules. Shares forfeited to meet tax obligation of restricted share vesting. Common stock acquired as a result of the 2013 performance based unit award vesting at 200% of the target award based on Gastar's share price appreciation over the performance period. Shares forfeited to meet tax obligation of performance based unit vesting. On July 10, 2014, the reporting person gifted 150,000 shares to his children in trusts for which the reporting person acts as the trustee as follows: The James Breckenridge Porter Trust of 2014 - 37,500 shares, The Grant Anderson Porter Trust of 2014 - 37,500 shares, The Addison Ann Porter Trust of 2014 - 37,500 shares and The Lily Madeline Porter Trust of 2014 - 37,500 shares. The reporting person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for the purposes of Section 16 or for any other purpose. These performance based units ("PBUs") vest ratably over a three-year performance period as previously reported. These PBUs vested and forfeited as a result of the 2014 PBU award settling at 0% of the target award based on Gastar's share price depreciation over the performance period. These PBUs vest in their entirety at the end of a three-year performance period as previously reported. These PBUs vest in their entirety at the end of the three-year performance period with settlement in common stock between 0% and 200% (**subject to limitations discussed in Footnote 11 below) of the target award based on Gastar's share price appreciation over a three-year performance period relative to a peer index. Share price appreciation is measured generally as the change in market value of common stock during the performance period. The PBUs have no voting rights but provide for dividend equivalents to be paid upon vesting. The number of PBUs reported (404,412) represents the target award. As such, the number of shares that may be issued upon vesting ranges from 0 shares to 808,824 shares. **As discussed in Footnote 10 above, at the end of the performance period, the participant may earn up to 200% of the target award, subject to a maximum award limitation of one million (1,000,000) shares that may be issued to any individual in a calendar year under the Gastar Exploration Inc. Long-Term Incentive Plan. /s/ J. Russell Porter, by Michael A. Gerlich as Attorney in Fact 2016-02-02