| 1 | C & R Petroleum Co. | Duncan, OK 73533-1341 | Oil & Gas Operator | Jun 2025 |
| 2 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Jun 2025 |
| 3 | Cabot Petroleum | | Oil & Gas Operator | Oct 1996 |
| 4 | Carl E Gungoll Exploration LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Jul 2025 |
| 5 | Casillas Petroleum Corp | Satanta, KS 67870 | Oil & Gas Operator | Jul 2025 |
| 6 | Castelli Exploration, Inc. | Oklahoma City, OK 73162 | Oil & Gas Operator | Jun 2025 |
| 7 | Castle Resources, Inc. | Russell, KS 67665 | Oil & Gas Operator | Jun 2025 |
| 8 | Centennial Energy Company | Torrance, CA 90503 | Oil Operator | Jan 2000 |
| 9 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | Aug 2025 |
| 10 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 11 | Charter Producti | | Oil & Gas Operator | Jun 1994 |
| 12 | Charter Production Company | Wichita, KS 67202 | Oil & Gas Operator | Feb 2018 |
| 13 | Chautauqua Oil And Gas LLC | Tulsa, OK 74145 | Oil & Gas Operator | Jun 2025 |
| 14 | Chesapeake Energy Marketing, Inc. | | Oil & Gas Operator | Jan 2025 |
| 15 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Oct 2025 |
| 16 | Chevron U S A In | | Oil & Gas Operator | Sep 2000 |
| 17 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 18 | Cig Exploration | Denver, CO 80201 | Oil & Gas Operator | Sep 1999 |
| 19 | Cimarex Energy Co. | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 20 | Cisco Operating LLC | Plano, TX 75024 | Oil & Gas Operator | Jun 2025 |
| 21 | Claassen Oil And Gas, Inc. | Estes Park, CO 80517 | Oil & Gas Operator | Jun 2025 |
| 22 | Clayton Corp Petro & NTRL Gas Prodn | Lakewood, CO 80228 | Oil & Gas Operator | Dec 2009 |
| 23 | Colorado Interst | | Gas Operator | Aug 1995 |
| 24 | Continental Ener | | Oil & Gas Operator | Dec 1996 |
| 25 | Continental Energy | Garden City, KS 67846-0918 | Oil & Gas Operator | Jul 2017 |
| 26 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Oct 2025 |
| 27 | Cox Edwin L & Be | | Oil & Gas Operator | Nov 1989 |
| 28 | Crawford Production Company Inc | Junction City, AR 71749 | Oil & Gas Operator | Jun 2025 |
| 29 | Cross Bar Petroleum, Inc. | Wichita, KS 67205 | Oil & Gas Operator | Jun 2016 |
| 30 | Cross Timbers Op | | Oil & Gas Operator | Nov 1996 |
| 31 | Cross Timbers Operating Co | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2025 |