| 1 | Alegre Energy Operating, LP | San Antonio, TX 78216 | Oil & Gas Operator | Sep 2005 |
| 2 | Alegre Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Dec 2024 |
| 3 | Altura Energy LTD. | Houston, TX 77210 | Oil & Gas Operator | Apr 2000 |
| 4 | Amax Oil & Gas Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 5 | Amen Oil LLC | Graham, TX 76450 | Oil & Gas Operator | Dec 2024 |
| 6 | American Energy-Perm Basin, LLC | Oklahoma City, OK 73113 | Oil & Gas Operator | May 2016 |
| 7 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 8 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 9 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Sep 2024 |
| 10 | Antelope Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2024 |
| 11 | Antelope Production Co. | Midland, TX 79701 | Oil & Gas Operator | Oct 1995 |
| 12 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Dec 2024 |
| 13 | Apex Operating Partners, LLC | San Angelo, TX 76902 | Gas Operator | Dec 2024 |
| 14 | Arch Oil & Gas, LLC | Dallas, TX 75254 | Oil & Gas Operator | Dec 2024 |
| 15 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 16 | Arden Energy Partners, Inc. | San Angelo, TX 76906 | Oil & Gas Operator | Feb 2013 |
| 17 | Ares Energy, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2024 |
| 18 | Arkland Producing Co Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2023 |
| 19 | Armor Petroleum, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 2024 |
| 20 | Athlon Energy Operating LLC | Denver, CO 80202 | Oil & Gas Operator | Apr 2014 |
| 21 | Athlon Fe Operating LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jan 2015 |
| 22 | Athlon Holdings LP | Denver, CO 80202 | Oil & Gas Operator | Jan 2015 |
| 23 | Atropos Exploration Company | Dallas, TX 75225 | Oil & Gas Operator | Dec 2024 |
| 24 | Audrey Oil & Gas LLC | Pampa, TX 79066 | Oil & Gas Operator | Dec 2024 |