| 1 | C & D Drilling Company | Hennepin, OK 73046 | Oil & Gas Operator | Mar 2007 |
| 2 | C & L Oil And Gas Corporation | Norman, OK 73069-8224 | Oil & Gas Operator | Jun 2025 |
| 3 | C.D. Operating Company, Inc. | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2015 |
| 4 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Jun 2025 |
| 5 | Callie Oil Company LLC | Perry, OK 73077 | Oil & Gas Operator | Jun 2025 |
| 6 | Calpine Natural Gas Company L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 7 | Calvert Drilling Company | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 1992 |
| 8 | Calvert Exploration Co | | Oil & Gas Operator | Apr 1993 |
| 9 | Camino Natural Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Jul 2025 |
| 10 | Canaan Energy Corporation | Oklahoma City, OK 73154-8806 | Oil & Gas Operator | Mar 2015 |
| 11 | Canvas Energy LLC | Oklahoma City, OK 73142-1839 | Oil & Gas Operator | Jul 2025 |
| 12 | Carbon Ridge Energy LLC | Norman, OK 73069 | Oil & Gas Operator | Jun 2025 |
| 13 | Carl E Gungoll Exploration Inc | Oklahoma City, OK 73154-0466 | Oil & Gas Operator | Jan 2016 |
| 14 | Carter Preston Drilling Co | Davis, OK 73030 | Gas Operator | Nov 2000 |
| 15 | Casillas Petroleum Corp | Satanta, KS 67870 | Oil & Gas Operator | Jul 2025 |
| 16 | Castella Inc | Bartlesville, OK 74003-3712 | Oil & Gas Operator | Jun 2025 |
| 17 | Castelli Exploration, Inc. | Oklahoma City, OK 73162 | Oil & Gas Operator | Jun 2025 |
| 18 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 19 | CBL Resources LLC | Tulsa, OK 74136-6308 | Oil & Gas Operator | Jun 2025 |
| 20 | CDS Oil Company | Tulsa, OK 74147-1514 | Oil & Gas Operator | Mar 2015 |
| 21 | CFC Oil Inc | Cyril, OK 73029-5601 | Oil & Gas Operator | Jun 2025 |
| 22 | Champion Reserves-Cri Inc | Oklahoma City, OK 73123 | Oil & Gas Operator | Jun 1994 |
| 23 | Charter Oak Production Co LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Oct 2025 |
| 24 | Chermac Energy Corporation | Edmond, OK 73083 | Oil & Gas Operator | Apr 2020 |
| 25 | Cherry, William H., Inc. | Oklahoma City, OK 73125 | Oil & Gas Operator | Mar 2015 |
| 26 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Oct 2025 |
| 27 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 28 | Cheyenne Petroleum Company | Oklahoma City, OK 73134 | Oil & Gas Operator | Oct 2025 |
| 29 | Chisholm Operating LLC | Oklahoma City, OK 73101-1502 | Oil & Gas Operator | Dec 2017 |
| 30 | Chizum Oil LLC | Wichita, KS 67211 | Oil & Gas Operator | Jun 2025 |
| 31 | Cimarex Energy Co. Of Colorado | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 32 | Cimarron Operating Company | Oklahoma City, OK 73112-3967 | Oil & Gas Operator | May 2011 |
| 33 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Oct 2025 |
| 34 | Citizen Energy II LLC | Tulsa, OK 74103-3729 | Oil & Gas Operator | Apr 2025 |
| 35 | Claremont Corporation | Tulsa, OK 74114 | Oil & Gas Operator | Feb 2017 |
| 36 | Claremont Exploration Inc | Tulsa, OK 74103-4107 | Oil & Gas Operator | Jun 1997 |
| 37 | Cleary Exploration LLC | Oklahoma City, OK 73112-7221 | Oil & Gas Operator | Oct 2014 |
| 38 | Coastal Oils Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2013 |
| 39 | Coastal Plains Energy Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2025 |
| 40 | Colonial Resources LLC | Edmond, OK 73003-3207 | Oil & Gas Operator | Aug 2019 |
| 41 | Columbia Production Company | Edmond, OK 73083 | Oil & Gas Operator | May 2020 |
| 42 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 43 | Combined Resources Corporation | Edmond, OK 73083 | Oil & Gas Operator | Oct 2025 |
| 44 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 45 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 46 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 47 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 48 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Oct 2025 |
| 49 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 50 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Oct 2025 |
| 51 | Contreras Al Consultants Inc | Oklahoma City, OK 73113-0762 | Oil & Gas Operator | Oct 2020 |
| 52 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 53 | Cook Oil Company | Wewoka, OK 74884 | Oil & Gas Operator | Sep 2015 |
| 54 | Cooper Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Jul 2025 |
| 55 | Cordillera Energy Partners LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | Mar 2020 |
| 56 | Corner Energy LLC | Oklahoma City, OK 73156-0548 | Oil & Gas Operator | Mar 2015 |
| 57 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 58 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 59 | Covington Oil Company Inc | Nichols Hills, OK 73116 | Oil & Gas Operator | Jun 2025 |
| 60 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 61 | CRB Resources Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Jun 2025 |
| 62 | Cross Timbers Operating Co | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2025 |
| 63 | Crown Energy Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Jun 2025 |
| 64 | Crystal Energy Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2019 |
| 65 | Cudd Operating Corp. | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2020 |
| 66 | Cummings Oil Company | Oklahoma City, OK 73112-6113 | Oil & Gas Operator | Jul 2025 |
| 67 | Czar Resources Inc | Houston, TX 77060 | Oil & Gas Operator | Oct 1992 |