| 1 | C & A Oil Company | Edmond, OK 73013-9413 | Oil & Gas Operator | Mar 2015 |
| 2 | C & D Supply | Cherokee, OK 73728-5817 | Oil & Gas Operator | Jan 2026 |
| 3 | C & D Supply LLC | Cherokee, OK 73728-5817 | Oil & Gas Operator | Feb 2026 |
| 4 | C & L Oil And Gas Corporation | Norman, OK 73069-8224 | Oil & Gas Operator | Feb 2026 |
| 5 | C D Operating Company Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2015 |
| 6 | C E D LC | Enid, OK 73702-0326 | Oil & Gas Operator | Oct 2021 |
| 7 | Canaan Energy Corporation | Oklahoma City, OK 73154-8806 | Oil & Gas Operator | Mar 2015 |
| 8 | Canvas Energy LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2026 |
| 9 | Canyon Creek Resources LLC | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2026 |
| 10 | Carbon Economy LLC | Chickasha, OK 73023 | Oil & Gas Operator | Feb 2026 |
| 11 | Carl Humphries Inc | Piedmont, OK 73078-0514 | Oil & Gas Operator | Feb 2026 |
| 12 | Carmen Field LP | Tulsa, OK 74135 | Oil & Gas Operator | Mar 2008 |
| 13 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 14 | Cates Betty J | Tulsa, OK 74112 | Oil & Gas Operator | Nov 2016 |
| 15 | Caulkins Oil Company | Aztec, NM 87410 | Oil & Gas Operator | Oct 2024 |
| 16 | Cayman Resources Corporation | Tulsa, OK 74119-1323 | Oil & Gas Operator | Jun 2001 |
| 17 | Ceja Corporation | Tulsa, OK 74172 | Oil & Gas Operator | Feb 2026 |
| 18 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | Feb 2026 |
| 19 | Champlin Exploration, Inc. | Enid, OK 73702 | Oil & Gas Operator | Feb 2026 |
| 20 | Chermac Energy Corporation | Edmond, OK 73083 | Oil & Gas Operator | Apr 2020 |
| 21 | Cherokee Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 22 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Apr 2026 |
| 23 | Chieftain Oil Co Inc | Kiowa, KS 67070 | Oil & Gas Operator | Feb 2026 |
| 24 | Chisholm Oil And Gas Operating LLC | Tulsa, OK 74103-3522 | Oil & Gas Operator | Feb 2026 |
| 25 | Cimarron Operating Company | Oklahoma City, OK 73112-3967 | Oil & Gas Operator | May 2011 |
| 26 | Citizen Energy III LLC | Devner, CO 80202 | Oil & Gas Operator | Jan 2026 |
| 27 | Citrus Energy Corporation | Castle Rock, CO 80104 | Oil & Gas Operator | Dec 2025 |
| 28 | Clay A Muegge | | Oil & Gas Operator | Feb 2026 |
| 29 | Cleary Exploration LLC | Oklahoma City, OK 73112-7221 | Oil & Gas Operator | Oct 2014 |
| 30 | Clifford Resources Inc | Oklahoma City, OK 73120 | Oil & Gas Operator | Jul 2015 |
| 31 | CLV Oil & Gas Inc | Tulsa, OK 74169-0713 | Oil & Gas Operator | Apr 2020 |
| 32 | CMS Nomeco Oil & Gas Co. | Jackson, MI 49201 | Oil & Gas Operator | Jan 2015 |
| 33 | Co-St Oil Operating Co Inc | Enid, OK 73706 | Oil & Gas Operator | Apr 1997 |
| 34 | COG Petroleum Corporation | Oklahoma City, OK 73116-7326 | Oil & Gas Operator | Mar 2019 |
| 35 | Collet Oil Ventures Inc | Denver, CO 80217 | Oil & Gas Operator | Jun 2004 |
| 36 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 37 | Combined Resources Corporation | Edmond, OK 73083 | Oil & Gas Operator | Apr 2026 |
| 38 | Compass Drilling Inc | Enid, OK 73702-5467 | Oil & Gas Operator | Sep 2014 |
| 39 | Compass Resources | Enid, OK 73702 | Oil & Gas Operator | Dec 2007 |
| 40 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 41 | Confed Oil Incorporated | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 42 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 43 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 44 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 45 | Continental Gas Inc | Enid, OK 73702-5103 | Oil & Gas Operator | Apr 2012 |
| 46 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Apr 2026 |
| 47 | Cortez Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2016 |
| 48 | Coterra Energy Operating Co. | Midland, TX 79706 | Oil & Gas Operator | Apr 2026 |
| 49 | Cox Gas Corporation | Dallas, TX 75201-7306 | Oil & Gas Operator | Apr 2015 |
| 50 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2026 |
| 51 | Cross Timbers Oil Company | Dallas, TX 75284 | Oil & Gas Operator | May 2013 |
| 52 | Cross Timbers Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2025 |
| 53 | Cross Timbers Production Co | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 2005 |
| 54 | Crown Central Pet Corp | Bellaire, TX 77401 | Oil & Gas Operator | Dec 2016 |
| 55 | Crown Energy Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Feb 2026 |
| 56 | Crusader Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2011 |
| 57 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 58 | Crusader Energy Group LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Mar 2015 |
| 59 | Crusader Energy II LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 60 | Crusader Energy III LLC | Oklahoma City, OK 73142-1856 | Oil & Gas Operator | Feb 2011 |
| 61 | Crystal Energy Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2019 |
| 62 | Culebra Oil & Gas, LLC | Kerrville, TX 78028 | Oil & Gas Operator | Apr 2026 |
| 63 | Curzon Operating Company LTD | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | Jan 2026 |