| 1 | C & H Oil Company | Ratliff City, OK 73481-0130 | Oil & Gas Operator | Apr 2015 |
| 2 | C & L Drilling Company | Ada, OK 74821-1252 | Oil & Gas Operator | Jan 2014 |
| 3 | C & L Enterprises Inc | Lindsay, OK 73052 | Oil & Gas Operator | Apr 2025 |
| 4 | C & L Oil Company | Cross Plains, TX 76443 | Oil & Gas Operator | Jul 2025 |
| 5 | C.J. Oil Company | Iowa Park, TX 76367 | Oil Operator | Dec 2024 |
| 6 | Cactus Oil & Gas LLC | Seminole, OK 74868-2430 | Oil & Gas Operator | Mar 2018 |
| 7 | Cajeza Energy | Drumright, OK 74030 | Oil & Gas Operator | May 2013 |
| 8 | Callie Oil Company LLC | Perry, OK 73077 | Oil & Gas Operator | May 2025 |
| 9 | Calvert Exploration Co | | Oil & Gas Operator | Apr 1993 |
| 10 | Cantrell Energy Corporation | Ada, OK 74820-0835 | Oil & Gas Operator | Apr 2025 |
| 11 | Cantrell Robert R | Ada, OK 74820 | Oil & Gas Operator | Apr 2025 |
| 12 | Canyon Creek Energy Arkoma LLC | Tulsa, OK 74120-3017 | Oil & Gas Operator | Apr 2025 |
| 13 | Cap Oil Company | Ada, OK 74820 | Oil Operator | Apr 2025 |
| 14 | Carmichael Oil & Gas Company | Vallejo, CA 94591-5653 | Oil & Gas Operator | Apr 2014 |
| 15 | Carver Harry | Oklahoma City, OK 73120 | Oil & Gas Operator | Nov 2000 |
| 16 | Cedar Oil Company | Midland, TX 79707 | Oil & Gas Operator | Jul 2025 |
| 17 | Center Oil Company | Ada, OK 74821-0584 | Oil Operator | May 2003 |
| 18 | Center Production Company LLC | Ada, OK 74820 | Oil Operator | Apr 2025 |
| 19 | Centrex Operating Company | Tulsa, OK 74105 | Oil & Gas Operator | Apr 2025 |
| 20 | Cep Mid-Continent LLC | Skiatook, OK 74070 | Oil & Gas Operator | Apr 2025 |
| 21 | Chapel Operating LLC | Lone Grove, OK 73443 | Oil Operator | Apr 2025 |
| 22 | Cherokee Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 23 | Cherokee Royalties & Minerals Inc | Duncan, OK 73533 | Oil & Gas Operator | May 2025 |
| 24 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Jul 2025 |
| 25 | Chiles Jack Well Service | Atwood, OK 74827-0373 | Oil Operator | Apr 2014 |
| 26 | Chiles Robert Morris | Allen, OK 74825 | Oil Operator | Apr 2025 |
| 27 | Chisum G H | Duncan, OK 73533 | Oil & Gas Operator | Dec 2010 |
| 28 | Christian Bros Op Co Inc | Ada, OK 74820 | Oil & Gas Operator | Apr 2014 |
| 29 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Jul 2025 |
| 30 | Clarita Operating LLC | Ada, OK 74821 | Oil Operator | Jun 2022 |
| 31 | Clark Krista | Ada, OK 74820-8595 | Oil Operator | Sep 2001 |
| 32 | Clean Oil LLC | Ada, OK 74820 | Oil & Gas Operator | Mar 2025 |
| 33 | Clifford Resources Inc | Oklahoma City, OK 73120 | Oil & Gas Operator | Jul 2015 |
| 34 | Clifton & Associates Inc | Tulsa, OK 74133 | Oil & Gas Operator | May 2020 |
| 35 | Coho Oil & Gas Inc | Coppell, TX 75019-8288 | Oil & Gas Operator | Mar 2015 |
| 36 | Colpitt C H Drilling Co LLC | Collinsville, OK 74021-7107 | Oil Operator | Apr 2025 |
| 37 | Colpitt Chas H Drilling Co | Collinsville, OK 74021-7105 | Oil & Gas Operator | Mar 2012 |
| 38 | Columbus Oil Company | Seminole, OK 74868 | Oil & Gas Operator | May 2025 |
| 39 | Complete Energy Services LLC | Gainesville, TX 76240 | Oil Operator | Aug 2022 |
| 40 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 41 | Conner Production Co LLC | Seminole, OK 74868 | Oil & Gas Operator | Apr 2025 |
| 42 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 43 | Consolidated Production Inc. | Seminole, OK 74868 | Oil & Gas Operator | Apr 2025 |
| 44 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Jul 2025 |
| 45 | Cook Oil Company | Wewoka, OK 74884 | Oil & Gas Operator | Sep 2015 |
| 46 | Crown Energy Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Apr 2025 |
| 47 | Crusader Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2011 |
| 48 | Crystal Energy Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2019 |