| 1 | C. J. Services | | Oil & Gas Operator | Sep 2016 |
| 2 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Jan 2026 |
| 3 | Cameron Oil & Gas Company | | Gas Operator | Dec 2016 |
| 4 | Cane Creek Energy, LLC | Charleston, WV 25314 | Oil & Gas Operator | Dec 2021 |
| 5 | Capital Energy, LLC | Ripley, WV 25271 | Oil & Gas Operator | Dec 2021 |
| 6 | Cenestia Energy Inc | | Oil & Gas Operator | Dec 1998 |
| 7 | Chesapeake Appalachia, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2025 |
| 8 | Columbia Gas Transmission, LLC | Charleston, WV 25314 | Oil & Gas Operator | Dec 2021 |
| 9 | Columbia Natural Resources, LLC | Charleston, WV 23502 | Oil & Gas Operator | Dec 2021 |
| 10 | Commonwealth Energy, Inc. | Weston, WV 26452-0000 | Oil & Gas Operator | Dec 2021 |
| 11 | Core Appalachia Operating LLC | Charleston, WV 25362 | Oil & Gas Operator | Dec 2024 |
| 12 | Cumberland Gas Co.(Tree Preservation Co) | | Oil & Gas Operator | Dec 1996 |