An extract/portion of Gastar's August 2015 investors' presentation. Marcellus Drilling News has extracted out only those slides dealing with information about their Marcellus/Utica operations. Slide #14 (page #43) shows the top 10 Utica dry gas wells as of August 2015 for all drillers. Gastar has two wells in the list.

1. 20© 2015 Gastar Exploration Inc.
MARCELLUS AND UTICA

2. 21© 2015 Gastar Exploration Inc.
Core Position in the Marcellus and Utica
 Core acreage proven in both the
Marcellus wet gas and the Utica dry gas
plays
 ~11,000 net acres in Marcellus and
8,600 leased (additional 1,900
pending(1)) net acres in dry Utica
 50% WI, 41.0% NRI
 Marshall & Wetzel Counties
 ~35,700 net acres in eastern area
 100% WI, 80% NRI
 Utica potential being studied
Acreage position lies near other leading players in the basin
1. 1,900 net acres pending includes acreage with lease negotiations in progress
2. As of 06/30/2015. Includes ~1,300 acres in Pennsylvania expiring 2015 and forward
Appalachia Overview Marcellus and Utica Map
~46,700 total net acres(2)
Marcellus
Fairway
Utica
Fairway
Utica
Dry Gas
Core
Gastar
West
Acreage
Gastar
East
Acreage

3. 22© 2015 Gastar Exploration Inc.
Infrastructure Overview
 Operational
 Improved run-time
 No flow restrictions expected
 Processing
 Total system capacity to 720
MMcf/d
 Central receipt point capacity –
155 MMcf/d
 Adequate takeaway capacity
 Firm transport
 50 MMBtu/d
 Additional firm available
 Water System
 14-mile system in Marshall County
 Reduced water costs from
$2.50/Bbl to $0.20/Bbl
 Supports both Marcellus and Utica
development

4. 23© 2015 Gastar Exploration Inc.
NE Basis
Source: Tudor Pickering Holt & Co January 2015 Midstream Bulletin
~15 Bcf/d of incremental takeaway capacity announced since YE 2013
• Gas and NGL basis differentials widened in 2015
• Gas infrastructure buildout to alleviate
• REX reversal to west August 1, 2015 1.8 Bcf

5. 24© 2015 Gastar Exploration Inc.
Marcellus Shale
Activity concentrated in liquids-rich portion of the play
1. Based on 06/30/15 Wright & Company, Inc. report utilizing SEC pricing
2. Based on EURs and related type curves developed by the Company using assumptions and methodologies described on page 3 of this presentation
Marshall & Wetzel Counties, W. Va.
 Atinum 50% JV Partner
 High Btu gas and condensate yields
 30–40 Bbls/MMcf condensate
 40–50 Bbls/MMcf NGLs (pre-ethane recovery)
Marcellus Core Statistics
 1P Reserves: 42.6 MMBoe(1)
 Q2’15 net production: 6.5 MBoe/d; 42% liquids
(11% oil)
 Remaining locations: gross 113, net 57
 51 gross PUDS
Summary Economics(2)
EUR Well Cost IRR PV-10
6.9 Bcfe $6.5MM 6% ($1.1MM)
Gross Appalachia Production

6. 25© 2015 Gastar Exploration Inc.
Marcellus Drilling Locations
Marcellus Shale Development
Development Plan
 Gastar has drilled and completed
74 gross (35.4 net) horizontal wells
and one vertical well to date
 Recent completions:
• Armstrong (7 wells) - 12/19/2014
• Hansen ( 3 wells) - 12/26/2014
• Goudy (3 wells) - 03/3/2015
• Hoyt (2 wells) - 4/5/2015
• Blake (2 wells) - 4/18/2015
 No further drilling in 2015
 No near term lease expirations
 42% HBP
 71% 2015/16 expirations include
automatic payment extensions
Marshall Co. - Marcellus Wells
Producing - 74
PUDS – 51
Wetzel Co. - Marcellus Wells
Producing - 1
Future Locations - 62
OHIO
West Virginia
OHIO
West Virginia

7. 26© 2015 Gastar Exploration Inc.
Utica Shale
Acreage position lies in core of the Dry Gas Window
1. 1,900 net acres pending includes acreage with lease negotiations in progress
2. Other operator production rates obtained from third-party company data, investor presentations, public filings and other sources that have not been independently verified by Gastar
Exploration Inc.
3. Based on 06/30/15 Wright & Company, Inc. report utilizing SEC pricing
4. Based on EURs and related type curves developed by the Company using assumptions and methodologies described on page 3 of this presentation
Overview
 Underlies core 11,100 acre Marcellus
position
 9,200 currently leased with an
additional 1,900 pending(1)
 Majority of Utica acreage is held by
Marcellus drilling
Utica Statistics
 1P Reserves: 10.7 MMBoe(3)
 Q2 2015 production: 6.8 MMcf/d (No
liquids)
 Pending locations: ~54 net
 6 PUDS
Summary Economics(4)
EUR Well Cost IRR PV-10
18.5 Bcf $13.0MM 10% $0.0MM
Utica Activity Map(2)
GPOR
30 MMcf/d
(Irons #4H)
GPOR
30 MMcf/d
(Irons #4H)
Hess
1 well
IP: 25 MMcfe/d
Hess
1 well
IP: 25 MMcfe/d
Rex
3 wells
IP: 18–19 MMcfe/d
Rex
3 wells
IP: 18–19 MMcfe/d
Antero
2 wells
IP: 20–22 MMcfe/d
Antero
2 wells
IP: 20–22 MMcfe/d
Antero
5 wells
IP: 37–53 MMcfe/d (peak)
Antero
5 wells
IP: 37–53 MMcfe/d (peak)
MHR
32 MMcf/d
(Stadler #3UH)
MHR
32 MMcf/d
(Stadler #3UH)
Eclipse
23 MMcf/d
(Tippens #6H)
Eclipse
23 MMcf/d
(Tippens #6H)
Gastar Simms U-5H
IP 29.4 MMcf/d
Gastar Simms U-5H
IP 29.4 MMcf/d
GPOR
2 wells
IP: 29–45 MMcfe/d
GPOR
2 wells
IP: 29–45 MMcfe/d
GPOR
IP: 21 MMcfe/d
Avg. 14 MMcfe/d in Q3 ’13
(Stutzman #1-14H)
GPOR
IP: 21 MMcfe/d
Avg. 14 MMcfe/d in Q3 ’13
(Stutzman #1-14H)
Utica
Dry Gas
Core
Utica
Fairway
OHIO
WEST
VIRGINIA
Gastar Blake U-7H
IP 36.8 MMcf/d
Gastar Blake U-7H
IP 36.8 MMcf/d
Rice
IP: 42 MMcfe/d
(Bigfoot #9H)
Rice
IP: 42 MMcfe/d
(Bigfoot #9H)
Chevron
25 MMcf/d
(Howard Conner #6H)
Chevron
25 MMcf/d
(Howard Conner #6H)
MHR
46.5 MMcf/d
(Stewart Winland #1300U)
MHR
46.5 MMcf/d
(Stewart Winland #1300U)
Stone Energy
IP 30.0 MMcf/d
(Pribble 6HU)
Stone Energy
IP 30.0 MMcf/d
(Pribble 6HU)
Range Resources
59 MMcf/d
1 well
Range Resources
59 MMcf/d
1 well
Southwestern
IP 25.0 MMcf/d
(Messenger 3H)
Southwestern
IP 25.0 MMcf/d
(Messenger 3H)
Eclipse
21.3 MMcf/d avg
(Shroyer 2H&4H)
Eclipse
21.3 MMcf/d avg
(Shroyer 2H&4H)

8. 27© 2015 Gastar Exploration Inc.
Utica Shale Development
Development Plan Utica Drilling Locations
 Blake well completed, 6,600’ lateral
with 34 stage frac
 ~$15.3MM D&C costs
 Only 6 of 108 gross locations in
PUD category
 Timing of additional Utica
development based on market
conditions
Utica Drilling Locations
Blake U-7H
6600’ Lateral Length
Simms U-5H
4447’ Lateral Length
Marshall Co. - Utica Wells
Producing - 2
Future Locations - 77
Wetzel Co. - Utica Wells
Future Locations - 31
West Virginia
OHIO
West Virginia
OHIO

9. 28© 2015 Gastar Exploration Inc.
Utica Shale Development
05/18/15
36.8
~6,235
6,617
34
21.7
18.3(1)
1.4(1)
Blake U-7H and Simms U-5H demonstrate the repeatability of dry gas Utica across
Gastar’s Marshall County position
Blake U-7H Simms U-5H
 Initial production date
 Initial 48 hours sales rate (MMcf/d)
 Flowing casing pressure psi
 Lateral length (feet)
 Frac stages
 30 day initial production (MMcf/d)
 ITD daily production average (MMcf/d)
 ITD cumulative production (Bcf)
08/29/14
29.4
~6,700
4,447
25
19.8
9.8(1)
3.1(1)
1. Daily production average as of 07/31/2015

10. 29© 2015 Gastar Exploration Inc.
Utica Acreage is the dry gas “Core of the Core”
Point Pleasant Shale Porosity Cross-Section
High Porosity
High TOC
High Carbonate Content
Lexington Shelf
Point Pleasant Shale Porosity Cross-Section
A A’
Up to 17%
Porosity
4-6% Porosity
GASTAR SIMMS U-5H
Landing pointVERY HIGH
PRESSRURE,
HIGH RATE
GAS WINDOW

11. 30© 2015 Gastar Exploration Inc.
Point Pleasant Paleogeography
Point Pleasant Paleography and SSTVD Structure
 Higher porosities in Pleasant Point are
associated with the depositional environment
of the Lexington Shelf Region
Point Pleasant SSTVD Structure
East and West Appalachian Acreage on same shelf with similar features
 Structure is very benign in Point Pleasant over
west acreage
 East Marcellus acreage appears prospective
in the Point Pleasant
Point Pleasant Paleogeography Source: After Wickstrom and others, 1992 and Cornell, 2000. Image from http://mcz.Harvard.edu/Departments/InvertPaleo/Trenton
Scotts Run Pad-EQT
3,221’ treated interval
24 hr. IP: 72.9 MMcf
22.6 MMcf / 1000’
8,641 psi flowing
casing pressure 0.95
pore pressure gradient

12. 31© 2015 Gastar Exploration Inc.
Appalachia Summary
53.3 MMBoe 1P reserves with SEC PV-10 of $75.9MM(1)
Appalachia Statistics
 1P Reserves: 53.3 MMBoe(1)
 1P PV–10: $75.9MM(1)
 ~ 57 net Marcellus locations on existing acreage
 ~ 54 net Utica locations on existing acreage
Net Drilling Locations
1. Based on 06/30/15 Wright & Company, Inc. report utilizing SEC pricing
 Complete 7.0 gross (3.5 net) Marcellus wells
 Complete 1.0 gross (0.5 net) Utica wells
2015 Capital Activity

13. 39© 2015 Gastar Exploration Inc.
APPENDIX

14. 43© 2015 Gastar Exploration Inc.
Utica Shale Development
1. Other operator data obtained from third-party company data, investor presentations, public filings and other sources that have not been independently verified by Gastar Exploration Inc.
Utica Dry Gas Comparative Statistics(1)

15. 44© 2015 Gastar Exploration Inc.
Point Pleasant Gross Isopach Thickness
GPOR
Irons #4H
IP: 30.3 MMcf/d
Eclipse
Tippens #6H
IP: 23.2 MMcf/d
MHR
Stalder #3UH
IP: 32.5 MMcf/d
GST
SIMMS U-5H
IP: 29.4 MMcf/d
BLAKE U-7H
IP: 36.8 MMcf/d
Low thickness variations in the Point Pleasant across Gastar’s acreage
CVX
Conner #6H
IP: 25 MMcf/d
Eclipse
Shroyer #2H & 4H
Combined IP: 42.5 MMcf/d
MHR
Stewart Winland #1300U
IP: 46.5 MMcf/d
EQT
Scotts Run Pad
IP: 72.9 MMcf/d

16. 45© 2015 Gastar Exploration Inc.
Utica Activity around Marshall & Wetzel Counties
1. Other operator data obtained from third-party company data, investor presentations, public filings and other sources that have not been independently verified by Gastar Exploration Inc.
(1)

17. 46© 2015 Gastar Exploration Inc.
Simms/Dangel Cross-Section
Statoil USA Onshore Prop Inc Dangel 1-H Gastar Simms U-5H
 5 Miles to west of Gastar’s acreage
 Porosity: 6 – 12%
 Net pay of +/- 74’
 Target Depth: 11,350’ TVD
 Porosity: Avg. 11% (up to 17%)
 Net pay of 92’

18. 48© 2015 Gastar Exploration Inc.
$0.63 $0.65
$0.77
$0.69
$0.00
$0.20
$0.40
$0.60
$0.80
$1.00
Marcellus Utica Mid-Continent Total Company
$0.79 $0.78
$0.01
$0.43
$0.00
$0.20
$0.40
$0.60
$0.80
$1.00
Marcellus Utica Mid-Continent Total Company
$3.63
$1.62
$8.04
$5.51
$2.53
$1.156,334
879
6,030
13,243
0
2,800
5,600
8,400
11,200
14,000
$0.00
$2.80
$5.60
$8.40
$11.20
$14.00
Marcellus Utica Mid‐Continent Total
Company
Total Direct Costs Daily Production
$2.21
$0.19
$7.27
$4.38
$2.53
$1.15
$9.80
$5.53
$0.00
$2.40
$4.80
$7.20
$9.60
$12.00
Marcellus Utica Mid-Continent Total Company
TransportationLease Operating Expense
Prod. Tax Total Direct Costs vs. Daily Production
Production Costs by Area – YTD’15 ($/Boe)
Note: Excludes impact of hedge gains and losses
$10.57
$6.66
Workover expense
Workover expense