| 1 | Cago, Inc. | College Sta, TX 77845 | Oil & Gas Operator | Oct 2025 |
| 2 | Calpine Natural Gas Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2002 |
| 3 | Calpine Natural Gas Company L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 4 | Calpine Natural Gas L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2006 |
| 5 | Camoil, Inc. | Columbus, TX 78934 | Oil & Gas Operator | Oct 2025 |
| 6 | Cannan, Morris | San Antonio, TX 78205 | Oil & Gas Operator | Oct 2025 |
| 7 | Carl Oil & Gas Co. | Bakersfield, CA 93309 | Oil & Gas Operator | Dec 1995 |
| 8 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 9 | Cavalier Oil & Gas, Inc. | Buchanan Dam, TX 78609 | Oil & Gas Operator | Oct 2025 |
| 10 | Cerberus Engineering, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 11 | Chain Oil & Gas, Inc. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 12 | Chalker Operating Inc. | Richmond, TX 77406 | Oil & Gas Operator | Jul 2016 |
| 13 | Channa Operating, LLC | Houston, TX 77063 | Oil & Gas Operator | Jul 2021 |
| 14 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 15 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Jun 2025 |
| 16 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 17 | Chroma Operating, Inc. | Washington, DC 20036 | Oil & Gas Operator | Jun 2016 |
| 18 | Cico Oil & Gas Company | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 19 | Cimarex Energy Co. | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 20 | Cimarex Energy Co. Of Colorado | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 21 | Cimarron Engineering, LLC | Kingsville, TX 78364 | Oil & Gas Operator | Oct 2025 |
| 22 | Clayton Williams Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2017 |
| 23 | Cleveland Production Company | Summit, MS 39666 | Oil & Gas Operator | Jul 1999 |
| 24 | Clide Oil Corp. | Iraan, TX 79744 | Oil & Gas Operator | Nov 2015 |
| 25 | CLS Interests, Incorporated | Austin, TX 78734 | Oil & Gas Operator | Jan 1997 |
| 26 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 27 | Coal Creek Energy, LLC | Overland Park, KS 66221 | Oil Operator | Dec 2019 |
| 28 | Coastal Expanse Oil & Gas | Austin, TX 78704 | Oil & Gas Operator | Oct 2025 |
| 29 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 30 | Coastal Production Company, Inc. | El Campo, TX 77437 | Oil & Gas Operator | Aug 1995 |
| 31 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 32 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Aug 2025 |
| 33 | Columbia Gas Development Corp. | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 34 | Columbia Production Company | Edmond, OK 73083 | Oil & Gas Operator | May 2020 |
| 35 | Concord Operating Incorporated | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Dec 2008 |
| 36 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 37 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Oct 2025 |
| 38 | Contango Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2025 |
| 39 | Contract Energy, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Oct 2012 |
| 40 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 41 | Core E & P Corp. | Victoria, TX 77902 | Oil & Gas Operator | Oct 2025 |
| 42 | Cornerstone Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Nov 2011 |
| 43 | Corum Production Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 44 | Crawford Energy Operating Co | Houston, TX 77056 | Oil & Gas Operator | Aug 2008 |
| 45 | Crawford Hughes Operating Co. | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 46 | Crest Resources & Expl. Corp. | Houston, TX 77079 | Oil & Gas Operator | Dec 1998 |
| 47 | Crimson Exploration Inc. | Houston, TX 77060 | Oil & Gas Operator | Apr 2006 |
| 48 | Crimson Exploration Oper., Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 49 | Crosspoint Energy Company | Dallas, TX 75205 | Oil & Gas Operator | Oct 2007 |
| 50 | Cxy Energy, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Nov 2000 |