| 1 | C And S Oil & Gas | San Antonio, TX 78217 | Oil & Gas Operator | Feb 1998 |
| 2 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Dec 2024 |
| 3 | Cag Petroleum Corp. | Dallas, TX 75382 | Oil & Gas Operator | Mar 2025 |
| 4 | Callon (Eagle Ford) LLC | Houston, TX 77042 | Oil & Gas Operator | Jun 2023 |
| 5 | Caribbean Energy, L.L.C. | Cotulla, TX 78014 | Oil & Gas Operator | Nov 2019 |
| 6 | Carrizo (Eagle Ford) LLC | Houston, TX 77042 | Oil & Gas Operator | Jan 2020 |
| 7 | Carrizo Exploration, Inc. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Aug 2016 |
| 8 | Carter E&P, LLC | Johnson City, TX 78636 | Oil & Gas Operator | Dec 2016 |
| 9 | Castle Gas Corporation | San Angelo, TX 76902 | Oil & Gas Operator | Oct 2014 |
| 10 | Catarina Petroleum L. C. | Dallas, TX 75228 | Oil & Gas Operator | Jun 2008 |
| 11 | Cavalier Oil & Gas, Inc. | Buchanan Dam, TX 78609 | Oil & Gas Operator | Mar 2025 |
| 12 | Ceniza Petroleum, Inc. | Portland, TX 78374 | Oil & Gas Operator | Mar 2025 |
| 13 | Centaur Exploration LLC | Evanston, WY 82931 | Oil & Gas Operator | Mar 2025 |
| 14 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2025 |
| 15 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Nov 2024 |
| 16 | Chi Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2025 |
| 17 | Christico Petroleum Company | San Antonio, TX 78216 | Oil & Gas Operator | Mar 2025 |
| 18 | Cibolo Energy Operating, Inc. | Bulverde, TX 78163 | Oil & Gas Operator | Mar 2025 |
| 19 | Cico Oil & Gas Company | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 20 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Mar 2025 |
| 21 | Civron Petroleum Res., LLC | San Antonio, TX 78229 | Oil & Gas Operator | Mar 2025 |
| 22 | Clark, John M. | Midland, TX 79701 | Oil & Gas Operator | Dec 1993 |
| 23 | Clipper Operating Co., Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jan 2000 |
| 24 | CML Exploration, LLC | Austin, TX 78746 | Oil & Gas Operator | Mar 2025 |
| 25 | Coates Energy Trust | San Antonio, TX 78209 | Oil & Gas Operator | Aug 2008 |
| 26 | Coho Resources Inc. | Dallas, TX 75240 | Oil & Gas Operator | Jul 2002 |
| 27 | Cole, Frank W Engineering | Dallas, TX 75254 | Oil & Gas Operator | Mar 2006 |
| 28 | Colt Operating Corporation | San Antonio, TX 78231 | Oil & Gas Operator | Aug 2003 |
| 29 | Columbia Gas Development Corp. | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 30 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 31 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Mar 2025 |
| 32 | Contango Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2025 |
| 33 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Mar 2025 |
| 34 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 35 | Conway Energy Oper Services Inc. | San Diego, TX 78384 | Oil & Gas Operator | Mar 2025 |
| 36 | Core E & P Corp. | Victoria, TX 77902 | Oil & Gas Operator | Mar 2025 |
| 37 | Cornerstone E & P Company LP | Irving, TX 75038 | Oil & Gas Operator | Nov 2010 |
| 38 | Crimson Energy Partners, L.P. | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2009 |
| 39 | Crimson Exploration Inc. | Houston, TX 77060 | Oil & Gas Operator | Apr 2006 |
| 40 | Crimson Exploration Oper., Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 41 | Cuatro Petro Corp. | Richardson, TX 75080 | Oil & Gas Operator | Mar 2025 |
| 42 | CW Dalcan Management SVCS, LTD. | Frisco, TX 75033 | Oil Operator | Mar 2025 |