| 1 | C E D LC | Enid, OK 73702-0326 | Oil & Gas Operator | Oct 2021 |
| 2 | C F & L Producing Co | | Oil & Gas Operator | Sep 2000 |
| 3 | Calumet Oil Company | Oklahoma City, OK 73114 | Oil & Gas Operator | Feb 2019 |
| 4 | Canok International Inc | Okmulgee, OK 74447 | Oil & Gas Operator | Jul 2025 |
| 5 | Canvas Energy LLC | Oklahoma City, OK 73142-1839 | Oil & Gas Operator | Jul 2025 |
| 6 | Capturepoint LLC | Allen, TX 75013 | Oil & Gas Operator | Oct 2025 |
| 7 | Cardinal River Operating LLC | Oklahoma City, OK 73102-7109 | Oil & Gas Operator | Jun 2025 |
| 8 | Carey Gas Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Jun 1999 |
| 9 | Carl E Gungoll Exploration LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Jul 2025 |
| 10 | Case Sales Company Inc | Tonkawa, OK 74653-0040 | Oil & Gas Operator | Jul 2025 |
| 11 | Casey Musgrove Oil Company Inc | Ponca City, OK 74602 | Oil & Gas Operator | Jun 2025 |
| 12 | Casillas Operating LLC | Tulsa, OK 74103-4060 | Oil & Gas Operator | Jun 2025 |
| 13 | Ceja Corporation | Tulsa, OK 74172 | Oil & Gas Operator | Jul 2025 |
| 14 | Centrex Operating Company | Tulsa, OK 74105 | Oil & Gas Operator | Jun 2025 |
| 15 | Challenge Operating Inc | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 16 | Chermac Energy Corporation | Edmond, OK 73083 | Oil & Gas Operator | Apr 2020 |
| 17 | Cherokee Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 18 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Oct 2025 |
| 19 | Chica Oil Company | Lago VIsta, TX 78645-6561 | Oil & Gas Operator | Mar 2001 |
| 20 | Chizum Oil LLC | Wichita, KS 67211 | Oil & Gas Operator | Jun 2025 |
| 21 | Christie Jr C B | Wichita Falls, TX 76308-4873 | Oil & Gas Operator | May 2024 |
| 22 | Cirrus Production Company | Enid, OK 73702 | Oil & Gas Operator | Jun 2025 |
| 23 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Oct 2025 |
| 24 | CLV Oil & Gas Inc | Tulsa, OK 74169-0713 | Oil & Gas Operator | Apr 2020 |
| 25 | Co-St Oil Operating Co Inc | Enid, OK 73706 | Oil & Gas Operator | Apr 1997 |
| 26 | Colpitt Brothers Oil | Collinsville, OK 74021 | Oil & Gas Operator | Apr 2020 |
| 27 | Colpitt Brothers Operating Co | Collinsville, OK 74021 | Oil & Gas Operator | Jun 2025 |
| 28 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 29 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 30 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 31 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 32 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Oct 2025 |
| 33 | Cooper Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Jul 2025 |
| 34 | Cordillera Energy Partners LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | Mar 2020 |
| 35 | Coronado Petroleum Corporation | Oklahoma City, OK 73102-4803 | Oil & Gas Operator | Jul 2025 |
| 36 | Covington Oil Company Inc | Nichols Hills, OK 73116 | Oil & Gas Operator | Jun 2025 |
| 37 | Cox Robert L | Blackwell, OK 74631 | Oil & Gas Operator | Mar 2025 |
| 38 | CPRC Inc | Tulsa, OK 74103-5037 | Oil & Gas Operator | Apr 1997 |
| 39 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 40 | Culp & Copple Oil Company | Cushing, OK 74023 | Oil & Gas Operator | Jun 2025 |