| 1 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Aug 2025 |
| 2 | Cardinal Energy | | Oil & Gas Operator | Dec 2008 |
| 3 | Carnegie Production Co | Charleston, WV 25328 | Oil & Gas Operator | Dec 2017 |
| 4 | Chesapeake Appalachia, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Sep 2025 |
| 5 | Clem Energy LLC | | Oil & Gas Operator | Dec 2021 |
| 6 | Clowser Well Service, Inc. | | Oil & Gas Operator | Dec 2021 |
| 7 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 8 | CNX Gas Company LLC | Canonsburg, PA 15317 | Oil & Gas Operator | Sep 2025 |
| 9 | Cobham Gas Industries, Inc. | | Oil & Gas Operator | Dec 2006 |
| 10 | Columbia Natural Resources, LLC | Charleston, WV 23502 | Oil & Gas Operator | Dec 2021 |
| 11 | Commonwealth Energy, Inc. | Weston, WV 26452-0000 | Oil & Gas Operator | Dec 2021 |
| 12 | Consol Gas Company | Canonsburg, PA 15317 | Oil & Gas Operator | Dec 2021 |
| 13 | Consolidation Coal Company | Saint Clairsville, OH 43950-8742 | Oil & Gas Operator | Dec 2020 |