| 1 | Calpine Natural Gas Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2002 |
| 2 | Calpine Natural Gas Company L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 3 | Calpine Natural Gas L.P. | Houston, TX 77002 | Oil & Gas Operator | Dec 2005 |
| 4 | Camden Resources, Inc. | Farmers BRNCH, TX 75234 | Oil & Gas Operator | Apr 2008 |
| 5 | Cameron, Paul E., Jr., Inc. | Montgomery, TX 77356 | Oil & Gas Operator | May 2015 |
| 6 | Cedar Point Oil Company | Baytown, TX 77520 | Oil & Gas Operator | Aug 2003 |
| 7 | Chain Oil & Gas, Inc. | Houston, TX 77024 | Oil & Gas Operator | Feb 2026 |
| 8 | Challenger Oil Inc | San Antonio, TX 78209 | Gas Operator | Feb 2026 |
| 9 | Chartex Petroleum Company | Houston, TX 77070 | Oil & Gas Operator | Aug 2000 |
| 10 | Chenango Oil And Gas Co. | Groves, TX 77619 | Oil & Gas Operator | Feb 2026 |
| 11 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Feb 2026 |
| 12 | Chilton Energy | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Sep 2006 |
| 13 | Chisholm Oil & Gas, LC | Buda, TX 78610 | Oil & Gas Operator | Feb 2026 |
| 14 | Choctaw Resources, Inc. | Aledo, TX 76008 | Oil & Gas Operator | Dec 2019 |
| 15 | Choice Exploration, Inc. | Irving, TX 75063 | Oil & Gas Operator | Feb 2026 |
| 16 | Christian Operating Company | Cypress, TX 77429 | Oil & Gas Operator | Dec 2014 |
| 17 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | Feb 2026 |
| 18 | CML Exploration, LLC | Austin, TX 78746 | Oil & Gas Operator | Feb 2026 |
| 19 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 20 | Coalinga Corporation | Houston, TX 77002 | Oil & Gas Operator | May 1999 |
| 21 | Cokinos, Inc. | Beaumont, TX 77701 | Oil & Gas Operator | Aug 2003 |
| 22 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 23 | Columbia Gas Development Corp. | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 24 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 25 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Feb 2026 |
| 26 | Contract Energy, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Oct 2012 |
| 27 | Core E & P Corp. | Victoria, TX 77902 | Oil & Gas Operator | Feb 2026 |
| 28 | Cornerstone Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Nov 2011 |
| 29 | Coronado Energy E&P Company, LLC | Houston, TX 77252 | Oil & Gas Operator | Dec 2010 |
| 30 | Costa Energy, LLC | Irving, TX 75063 | Oil & Gas Operator | Feb 2026 |
| 31 | Costilla Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 32 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 33 | Crawford Energy Operating Co | Houston, TX 77056 | Oil & Gas Operator | Aug 2008 |
| 34 | Crawford Hughes Operating Co. | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2026 |
| 35 | Crimson Exploration Oper., Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 36 | Cross Timbers Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2025 |
| 37 | Crown Petroleum Corp. | Oklahoma City, OK 73106 | Oil & Gas Operator | Feb 2026 |
| 38 | CWC Oil & Gas, LLC | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 39 | Cxy Energy, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Nov 2000 |