| 1 | Campbell Oil & Gas Inc | Indiana, PA 15701-0278 | Oil & Gas Operator | Dec 2025 |
| 2 | Capital Oil & Gas Inc | Austintown, OH 44515-3033 | Oil & Gas Operator | Dec 2025 |
| 3 | Carlon Oil & Gas Co Inc | Derby, KS 67037 | Gas Operator | Dec 2025 |
| 4 | Castle Gas Company Inc | Pittsburgh, PA 15236-2466 | Oil & Gas Operator | Dec 2007 |
| 5 | Catalyst Energy Inc | Pittsburgh, PA 15218 | Oil & Gas Operator | Dec 2025 |
| 6 | Chance Gas & Oil LLC | Clymer, PA 15728-6318 | Gas Operator | Dec 2025 |
| 7 | Cline Oil Inc | Bradford, PA 16701 | Oil & Gas Operator | Dec 2025 |
| 8 | CNG Development Co | | Oil & Gas Operator | Dec 2008 |
| 9 | CNX Gas Company LLC | Canonsburg, PA 15317 | Oil & Gas Operator | Dec 2025 |
| 10 | Colonial Hardwoods Inc | Luthersburg, PA 15848-3506 | Gas Operator | Dec 2019 |
| 11 | Columbia Gas Trans LLC | Charleston, WV 25325-1273 | Gas Operator | Dec 1987 |
| 12 | Consol Gas Company | Canonsburg, PA 15317 | Oil & Gas Operator | Dec 2021 |
| 13 | Coolspring Gas & Oil Co LLC | Coolspring, PA 15730-8524 | Gas Operator | Dec 2025 |
| 14 | Coterra Energy Inc | Coraopolis, PA 15108-9862 | Oil & Gas Operator | Dec 2025 |
| 15 | Cottonwood Prod Co Inc | Buffalo, NY 14202-2212 | Gas Operator | Dec 2002 |