| 1 | Abarta Oil & Gas Co., Inc. | Pittsburgh, PA 15238 | Oil & Gas Operator | Dec 2020 |
| 2 | Actagon Corp | | Oil & Gas Operator | Dec 2025 |
| 3 | Adobe Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 4 | Alcove Investments | Apollo, PA 15613-9720 | Oil & Gas Operator | Dec 2025 |
| 5 | Allegheny Natural Resources Inc | Gibsonia, PA 15044-8055 | Gas Operator | Dec 2019 |
| 6 | Alliance Petroleum Corp | Canton, OH 44718-2553 | Oil & Gas Operator | Mar 2026 |
| 7 | Amer Exploration Co | Plymouth Meeting, PA 19462-1640 | Oil & Gas Operator | Dec 2008 |
| 8 | Amer Natural Resources LLC | Rural Valley, PA 16249-0306 | Oil & Gas Operator | Dec 2018 |
| 9 | Ams Energy LLC | Herman, PA 16039-0156 | Oil & Gas Operator | Mar 2026 |
| 10 | Ancient Sands Inc | Kittanning, PA 16201-0916 | Oil & Gas Operator | Dec 2025 |
| 11 | Angerman Assoc Inc | Pittsburgh, PA 15238-1359 | Oil & Gas Operator | Dec 1998 |
| 12 | Apex Energy (Pa) LLC | Canonsburg, PA 15317-6523 | Gas Operator | May 2025 |
| 13 | Apollo Gas Co | Pittsburgh, PA 15236-1435 | Gas Operator | Dec 1991 |
| 14 | Apollo Resources LLC | Vintondale, PA 15961-0222 | Oil & Gas Operator | Mar 2026 |
| 15 | Appalachian Energy Inc | Pittsburgh, PA 15220 | Gas Operator | Dec 2008 |
| 16 | Ark Resources Inc | Indiana, PA 15701-0069 | Oil & Gas Operator | Dec 2014 |
| 17 | Armstrong Gas Co LLC | Kittanning, PA 16201-2269 | Oil & Gas Operator | Dec 2018 |
| 18 | Atlas Resources Inc | Coraopolis, PA 15108-0611 | Oil & Gas Operator | Dec 2007 |
| 19 | Atlas Resources LLC | Pittsburgh, PA 15275-1033 | Oil & Gas Operator | Jun 2018 |