| 1 | Campbell Oil & Gas Inc | Indiana, PA 15701-0278 | Oil & Gas Operator | Feb 2024 |
| 2 | Carnegie Natural Gas Co | Pittsburgh, PA 15236-1435 | Gas Operator | Dec 1991 |
| 3 | Carnegie Production Co | Charleston, WV 25328 | Oil & Gas Operator | Dec 2017 |
| 4 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 5 | Castle Gas Company Inc | Pittsburgh, PA 15236-2466 | Oil & Gas Operator | Dec 2007 |
| 6 | Chesapeake Appalachia LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2024 |
| 7 | Chestnut Ridge Storage LLC | San Diego, CA 92121-1008 | Gas Operator | Dec 2019 |
| 8 | CNX Gas Company LLC | Canonsburg, PA 15317 | Oil & Gas Operator | Feb 2024 |
| 9 | Columbia Gas Trans LLC | Charleston, WV 25325-1273 | Gas Operator | Dec 1987 |
| 10 | Columbia Natural Res Inc | Charleston, WV 25362-0070 | Gas Operator | Dec 2008 |
| 11 | Columbia Natural Resources, LLC | Charleston, WV 23502 | Oil & Gas Operator | Dec 2021 |
| 12 | Consol Gas Company | Canonsburg, PA 15317 | Oil & Gas Operator | Dec 2021 |
| 13 | Coterra Energy Inc | Pittsburgh, PA 15275-1121 | Oil & Gas Operator | Feb 2024 |
| 14 | Cottonwood Prod Co Inc | Buffalo, NY 14202-2212 | Gas Operator | Dec 2002 |