| 1 | Abarta Oil & Gas Co., Inc. | Pittsburgh, PA 15238 | Oil & Gas Operator | Dec 2020 |
| 2 | Actagon Corp | Monroeville, PA 15146 | Oil & Gas Operator | Dec 2024 |
| 3 | Add Energy Co | Butler, PA 16002-0471 | Gas Operator | Dec 2020 |
| 4 | Adobe Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 5 | Afco Energy Prod Co | Indiana, PA 15701-0538 | Oil & Gas Operator | Dec 2019 |
| 6 | Alcove Investments | Apollo, PA 15613-9720 | Oil & Gas Operator | Dec 2024 |
| 7 | Angerman Assoc Inc | Pittsburgh, PA 15238-1359 | Oil & Gas Operator | Dec 1998 |
| 8 | Apollo Gas Co | Pittsburgh, PA 15236-1435 | Gas Operator | Dec 1991 |
| 9 | Apollo Resources LLC | Vintondale, PA 15961-0222 | Oil & Gas Operator | Jul 2025 |
| 10 | Ark Resources Inc | Indiana, PA 15701-0069 | Oil & Gas Operator | Dec 2014 |
| 11 | Armstrong Gas Co LLC | Kittanning, PA 16201-2269 | Oil & Gas Operator | Dec 2018 |
| 12 | Atlas Resources Inc | Coraopolis, PA 15108-0611 | Oil & Gas Operator | Dec 2007 |
| 13 | Atlas Resources LLC | Pittsburgh, PA 15275-1033 | Oil & Gas Operator | Jun 2018 |