| 1 | C. J. Filson, LLC | Protection, KS 67127 | Gas Operator | Aug 2014 |
| 2 | Cambron, Paul L. | Ness City, KS 67560 | Oil & Gas Operator | Dec 2019 |
| 3 | Canaday Oil Corp | Goddard, KS 67052 | Oil & Gas Operator | Dec 2024 |
| 4 | Castelli Exploration, Inc. | Oklahoma City, OK 73162 | Oil & Gas Operator | Jan 2025 |
| 5 | Charter Producti | | Oil & Gas Operator | Jun 1994 |
| 6 | Chesapeake Energy Marketing, Inc. | | Oil & Gas Operator | Dec 2024 |
| 7 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Apr 2025 |
| 8 | Clark Exploration Co. | Highlands Ranch, CO 80126-7645 | Oil & Gas Operator | Nov 2024 |
| 9 | Cleary Petroleum Corporation | Edmond, OK 73083 | Oil & Gas Operator | Jul 2019 |
| 10 | Clute Oil Corporation | Cherry Hills VIllage, CO 80113 | Oil & Gas Operator | Dec 2024 |
| 11 | Cody Resources, Inc. | Midland, TX 79705 | Oil & Gas Operator | Sep 2002 |
| 12 | Comanche Resources Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2025 |
| 13 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 14 | Continental Ener | | Oil & Gas Operator | Dec 1996 |
| 15 | Coral Coast Petroleum, L.C. | Wichita, KS 67226 | Oil & Gas Operator | Nov 2019 |
| 16 | Corsair Energy, LC | Wichita, KS 67202 | Oil & Gas Operator | Apr 2004 |
| 17 | Cotton Petroleum | | Oil & Gas Operator | May 1988 |