| 1 | Abarta Oil & Gas Co., Inc. | Pittsburgh, PA 15238 | Oil & Gas Operator | Dec 2020 |
| 2 | Adobe Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 3 | Amer Exploration Co | Plymouth Meeting, PA 19462-1640 | Oil & Gas Operator | Dec 2008 |
| 4 | Angerman Assoc Inc | Pittsburgh, PA 15238-1359 | Oil & Gas Operator | Dec 1998 |
| 5 | Apex Energy (Pa) LLC | Wexford, PA 15090-7383 | Gas Operator | Feb 2024 |
| 6 | Apollo Gas Co | Pittsburgh, PA 15236-1435 | Gas Operator | Dec 1991 |
| 7 | Apollo Resources LLC | Vintondale, PA 15961-0222 | Oil & Gas Operator | Feb 2024 |
| 8 | Ark Resources Inc | Indiana, PA 15701-0069 | Oil & Gas Operator | Dec 2014 |
| 9 | Armstrong Gas Co LLC | Kittanning, PA 16201-2269 | Oil & Gas Operator | Dec 2018 |
| 10 | Atlas Resources Inc | Coraopolis, PA 15108-0611 | Oil & Gas Operator | Dec 2007 |
| 11 | Atlas Resources LLC | Pittsburgh, PA 15275-1033 | Oil & Gas Operator | Jun 2018 |