| 1 | C & V Oil And Gas | Marietta, OH 45750 | Oil & Gas Operator | Dec 2011 |
| 2 | C G O Inc | Wheeling, WV 26003 | Oil & Gas Operator | Dec 2024 |
| 3 | Ca-Dora Inc | Waterford, OH 45786 | Oil & Gas Operator | Dec 1984 |
| 4 | Carl E Smith Petroleum Inc | Dallas, TX 75234-6057 | Oil & Gas Operator | Dec 2019 |
| 5 | Carless Resources Inc | Cambridge, OH 43725 | Oil & Gas Operator | Dec 1997 |
| 6 | Carlton Oil Corp | Newport, OH 45768 | Oil & Gas Operator | Dec 2013 |
| 7 | Carper Well Service Inc. | Reno, OH 45773 | Oil & Gas Operator | Dec 2023 |
| 8 | Cedar Valley Energy Inc | Wooster, OH 44691 | Oil & Gas Operator | Dec 2021 |
| 9 | Cemco Operating Inc | Bartlet, OH 45713 | Oil & Gas Operator | Dec 2005 |
| 10 | Century Well Service | Cumberland, WV 26047 | Oil & Gas Operator | Dec 2006 |
| 11 | Cgas Exploration | Charleston, WV 25301 | Oil & Gas Operator | Dec 2006 |
| 12 | Chesapeake Appalachia, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Aug 2025 |
| 13 | Chevron Appalachia, LLC | Corapolis, PA 15108 | Oil & Gas Operator | Jul 2020 |
| 14 | Christa Oil Co | Cumberland, OH 43732 | Oil & Gas Operator | Nov 1999 |
| 15 | Citation Energy Company | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 16 | Clinton Gas Marketing Inc | Columbus, OH 43214 | Oil & Gas Operator | Dec 1988 |
| 17 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 18 | Collins-McGregor Operating Company | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 19 | Columbia Gas Transmission, LLC | Charleston, WV 25314 | Oil & Gas Operator | Dec 2021 |
| 20 | Compro Services Inc | Williamstown, WV 26187 | Oil & Gas Operator | Dec 1985 |
| 21 | Conley Energy Co LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2020 |
| 22 | Connoil LLC | Grove City, OH 43123 | Oil & Gas Operator | Dec 2024 |
| 23 | Consolidated Res Of Amer | Cincinnati, OH 45208 | Oil & Gas Operator | Dec 1996 |
| 24 | Constitution Investment Co LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 25 | Constitution Petroleum | Salt Lake City, UT 84124-1110 | Oil & Gas Operator | Dec 2008 |
| 26 | Corning Oil Co Inc | Sonora, OH 43785 | Oil & Gas Operator | Dec 2002 |
| 27 | Cosgriff Joe | Detroit, MI 48208 | Oil & Gas Operator | Dec 1998 |
| 28 | Creighton Rick D | New Matamoras, OH 45767 | Oil & Gas Operator | Dec 2016 |
| 29 | Crest Petroleum | Newark, OH 43055 | Oil & Gas Operator | Nov 1993 |
| 30 | Cutter Exploration Inc | Oviedo, FL 32765 | Oil & Gas Operator | Dec 2024 |
| 31 | Cuyahoga Expl & Develop | Marietta, OH 45750 | Oil & Gas Operator | Dec 1986 |