| 1 | Abel, M.D. Co. | Lampasas, TX 76550 | Oil & Gas Operator | Jun 2017 |
| 2 | Abraxas Petroleum Corporation | San Antonio, TX 78259 | Oil & Gas Operator | Mar 2025 |
| 3 | Abraxas Production Corporation | San Antonio, TX 78270 | Oil & Gas Operator | Sep 1999 |
| 4 | Aggietech Oil, LTD. | Midland, TX 79701 | Oil & Gas Operator | Aug 2016 |
| 5 | Alaron Energy, Inc. | Irving, TX 75038 | Oil & Gas Operator | Mar 2025 |
| 6 | Allegro Operating, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2025 |
| 7 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 8 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 9 | Americo Energy Resources, LLC | Houston, TX 77063 | Oil & Gas Operator | Mar 2025 |
| 10 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 11 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Dec 2024 |
| 12 | Antelope Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2024 |
| 13 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Mar 2025 |
| 14 | Arkoma Prod Co Of Texas, Inc. | Dallas, TX 75225 | Oil Operator | May 2004 |
| 15 | Armor Petroleum Inc | Wichita Falls, TX 76308 | Oil & Gas Operator | Mar 2025 |
| 16 | Astin Corp. | Dallas, TX 75229 | Oil & Gas Operator | Sep 1994 |
| 17 | Atapco | Houston, TX 77040 | Oil & Gas Operator | Feb 1999 |
| 18 | Atlas Energy Corporation (Del.) | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2025 |
| 19 | Atmos Pipeline - Texas | Dallas, TX 75240 | Oil & Gas Operator | Mar 2025 |