| 1 | C & G Energy Inc | | Oil & Gas Operator | Jun 1996 |
| 2 | C E D LC | Enid, OK 73702-0326 | Oil & Gas Operator | Oct 2021 |
| 3 | C&D Supply | Cherokee, OK 73728-5817 | Oil & Gas Operator | Jun 2025 |
| 4 | C.D. Operating Company, Inc. | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2015 |
| 5 | Canaan Energy Corporation | Oklahoma City, OK 73154-8806 | Oil & Gas Operator | Mar 2015 |
| 6 | Canvas Energy LLC | Oklahoma City, OK 73142-1839 | Oil & Gas Operator | Jul 2025 |
| 7 | Canyon Creek Resources LLC | Tulsa, OK 74136 | Oil & Gas Operator | Oct 2025 |
| 8 | Capitol Well Servicing Co., Inc. | Oklahoma City, OK 73143 | Oil & Gas Operator | May 2023 |
| 9 | Capmac Inc | Tulsa, OK 74105-7119 | Oil & Gas Operator | Jan 2007 |
| 10 | Carl E Gungoll Exploration Inc | Oklahoma City, OK 73154-0466 | Oil & Gas Operator | Jan 2016 |
| 11 | Carl E Gungoll Exploration LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Jul 2025 |
| 12 | Casillas Petroleum Corp | Satanta, KS 67870 | Oil & Gas Operator | Jul 2025 |
| 13 | Caulkins Oil Company | Aztec, NM 87410 | Oil & Gas Operator | Oct 2024 |
| 14 | Ceja Corporation | Tulsa, OK 74172 | Oil & Gas Operator | Jul 2025 |
| 15 | CH4 Energy II LLC | Fort Worth, TX 76109 | Oil & Gas Operator | Apr 2018 |
| 16 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | Aug 2025 |
| 17 | Challenge Operating Inc | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 18 | Champlin Exploration, Inc. | Enid, OK 73702 | Oil & Gas Operator | Jul 2025 |
| 19 | Charter Oak Production Co LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Oct 2025 |
| 20 | Chermac Energy Corporation | Edmond, OK 73083 | Oil & Gas Operator | Apr 2020 |
| 21 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Oct 2025 |
| 22 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 23 | Cirrus Production Company | Enid, OK 73702 | Oil & Gas Operator | Jun 2025 |
| 24 | Cisco Operating LLC | Plano, TX 75024 | Oil & Gas Operator | Jun 2025 |
| 25 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Oct 2025 |
| 26 | Cities Services Company | | Oil & Gas Operator | Mar 2008 |
| 27 | Citrus Energy Corporation | Castle Rock, CO 80104 | Oil & Gas Operator | Mar 2020 |
| 28 | Claremont Exploration Inc | Tulsa, OK 74103-4107 | Oil & Gas Operator | Jun 1997 |
| 29 | Cleary Exploration LLC | Oklahoma City, OK 73112-7221 | Oil & Gas Operator | Oct 2014 |
| 30 | Cleary Petroleum Corporation | Edmond, OK 73083 | Oil & Gas Operator | Jul 2019 |
| 31 | Clements Exploration Co | Oklahoma City, OK 73132-5922 | Oil & Gas Operator | Jan 2006 |
| 32 | CLV Oil & Gas Inc | Tulsa, OK 74169-0713 | Oil & Gas Operator | Apr 2020 |
| 33 | Co-St Oil Operating Co Inc | Enid, OK 73706 | Oil & Gas Operator | Apr 1997 |
| 34 | Cochran Industrial Corporation | Cushing, OK 74023-1427 | Oil & Gas Operator | Apr 2001 |
| 35 | Columbus Oil Company | Seminole, OK 74868 | Oil & Gas Operator | Jul 2025 |
| 36 | Combined Resources Corporation | Edmond, OK 73083 | Oil & Gas Operator | Oct 2025 |
| 37 | Compass Drilling Inc | Enid, OK 73702-5467 | Oil & Gas Operator | Sep 2014 |
| 38 | Compass Resources | Enid, OK 73702 | Oil & Gas Operator | Dec 2007 |
| 39 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 40 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 41 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 42 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Oct 2025 |
| 43 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Oct 2025 |
| 44 | Contreras Al Consultants Inc | Oklahoma City, OK 73113-0762 | Oil & Gas Operator | Oct 2020 |
| 45 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 46 | Cooper Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Jul 2025 |
| 47 | Cordillera Energy Partners LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | Mar 2020 |
| 48 | Corwin, B. V. | Enid, OK 73701 | Oil & Gas Operator | Apr 2017 |
| 49 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 50 | Cross Timbers Operating Co | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2025 |
| 51 | Cross Timbers Production Co | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 2005 |
| 52 | Crown Central Pet Corp | Bellaire, TX 77401 | Oil & Gas Operator | Dec 2016 |
| 53 | Crown Energy Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Jun 2025 |
| 54 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 55 | Crusader Energy Group LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Mar 2015 |
| 56 | Crusader Energy II LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 57 | Crusader Energy III LLC | Oklahoma City, OK 73142-1856 | Oil & Gas Operator | Feb 2011 |
| 58 | Cummings Oil Company | Oklahoma City, OK 73112-6113 | Oil & Gas Operator | Jul 2025 |