| 1001 | Culoco, Inc. | Dallas, TX 75374 | Oil & Gas Operator | Nov 2024 |
| 1002 | Culver & Cain Production LLC | Tyler, TX 75711 | Oil & Gas Operator | Jul 2025 |
| 1003 | Cumberland Petroleum, Inc. II | Weatherford, TX 76086 | Oil & Gas Operator | May 1997 |
| 1004 | Cumming Company, Inc. The | Fort Worth, TX 76116 | Oil & Gas Operator | Jul 2025 |
| 1005 | Cummings, C. M. Oil & Gas | Lewisville, TX 75029 | Oil & Gas Operator | Nov 1993 |
| 1006 | Cummins & Walker Oil Co., Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2021 |
| 1007 | Cundiff Operating Company | Dallas, TX 75238 | Oil & Gas Operator | Jul 2025 |
| 1008 | Curmar Producers | Adairsville, GA 30103 | Oil Operator | Mar 2008 |
| 1009 | Currie Cattle Co. | Big Spring, TX 79720 | Oil & Gas Operator | Sep 2007 |
| 1010 | Curzac Oil And Gas, LLC | Plano, TX 75075 | Oil & Gas Operator | Jul 2025 |
| 1011 | Custer & Wright Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 1012 | Cutbow Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Jul 2025 |
| 1013 | Cuyahoga Expl. & Devel. Corp. | Jericho, NY 11753 | Oil & Gas Operator | Dec 1996 |
| 1014 | CVR Supply & Trading, LLC | Sugar Land, TX 77479 | Oil & Gas Operator | Apr 2024 |
| 1015 | CVS Operating, LLC. | Plano, TX 75074 | Oil & Gas Operator | Jul 2025 |
| 1016 | CVS Production, LLC. | Plano, TX 75074 | Oil Operator | Jul 2025 |
| 1017 | CW Dalcan Management SVCS, LTD. | Frisco, TX 75033 | Oil Operator | Jul 2025 |
| 1018 | CWC Oil & Gas, LLC | Abilene, TX 79608 | Oil & Gas Operator | Jul 2025 |
| 1019 | CWD Resources, LLC | Kilgore, TX 75663 | Oil Operator | Jul 2025 |
| 1020 | CWF Energy, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1997 |
| 1021 | Cwic, Inc. | Granbury, TX 76049 | Oil & Gas Operator | Jul 2025 |
| 1022 | Cwo Energy, LLC | Midland, TX 79705 | Oil Operator | Jul 2025 |
| 1023 | Cwoc | Big Spring, TX 79721 | Oil & Gas Operator | Jul 2025 |
| 1024 | CWS Aceite Operating, Inc. | Cotulla, TX 78014 | Oil & Gas Operator | Aug 2018 |
| 1025 | CX Operating LLC | Dallas, TX 75238 | Oil & Gas Operator | Jul 2025 |
| 1026 | CXL Energy LLC | Canada, 00100 | Oil & Gas Operator | Jul 2025 |
| 1027 | Cxy Energy, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Nov 2000 |
| 1028 | Cyber Enviro-Tech Inc | | Oil & Gas Operator | Jul 2025 |
| 1029 | Cycle Oil & Gas Inc. | Katy, TX 77449 | Oil Operator | Jul 2025 |
| 1030 | Cyclone Exploration, Inc. | Florence, CO 81226 | Oil & Gas Operator | Jul 2025 |
| 1031 | Cymri Corporation, The | Houston, TX 77057 | Oil & Gas Operator | Mar 2008 |
| 1032 | Cymri, L.L.C. | Houston, TX 77042 | Oil & Gas Operator | Jul 2025 |
| 1033 | Cynpat Oil & Gas, Inc. | Sulphur SPGS, TX 75482 | Oil Operator | Nov 2018 |
| 1034 | Cypress E & P Corporation | Leander, TX 78646 | Oil & Gas Operator | Sep 2016 |
| 1035 | Cypress Operating, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jul 2025 |
| 1036 | Cypress Partners, Inc. | Houston, TX 77068 | Oil & Gas Operator | May 1999 |
| 1037 | Cypress Production, Inc. | Azle, TX 76020 | Oil & Gas Operator | Jul 2025 |