| 1 | C. H. Todd, Inc. | Wichita, KS 67212 | Oil & Gas Operator | Dec 2019 |
| 2 | Calvin Explorati | | Oil & Gas Operator | Oct 1991 |
| 3 | Canaday Oil Corp | Goddard, KS 67052 | Oil & Gas Operator | Aug 2024 |
| 4 | Carmen Schmitt, Inc. | Great Bend, KS 67530 | Oil & Gas Operator | Aug 2024 |
| 5 | Centrex Operating Company | Tulsa, OK 74105 | Oil & Gas Operator | Oct 2024 |
| 6 | Charter Producti | | Oil & Gas Operator | Jun 1994 |
| 7 | Charter Production Company | Wichita, KS 67202 | Oil & Gas Operator | Feb 2018 |
| 8 | Chesapeake Operating, LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Dec 2024 |
| 9 | Citadel Production Company, Inc. | Denver, CO 80201 | Oil Operator | Sep 1996 |
| 10 | Claassen Oil And Gas, Inc. | Estes Park, CO 80517 | Oil & Gas Operator | Aug 2024 |
| 11 | Clarco Gas Co., Inc. | Westmont, IL 60559 | Oil Operator | Dec 2011 |
| 12 | Clayton Corporation | Golden, CO 80401 | Oil & Gas Operator | Dec 2019 |
| 13 | Clothier, David W. | Eastborough, KS 67206 | Oil & Gas Operator | Dec 2019 |
| 14 | Cobra Oil & Gas | | Oil & Gas Operator | Jul 1995 |
| 15 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 2024 |
| 16 | Coral Coast Petroleum, L.C. | Wichita, KS 67226 | Oil & Gas Operator | Nov 2019 |
| 17 | Crescent Drillin | | Gas Operator | Apr 1991 |