| 1 | Advantage Resources Inc | Broomfield, CO 80020 | Oil & Gas Operator | Jun 2025 |
| 2 | Aec Oil & Gas USA Inc | Denver, CO 80202 | Oil & Gas Operator | May 2004 |
| 3 | Alberta Gas Company | Vernal, UT 84078 | Oil & Gas Operator | Nov 2021 |
| 4 | Alta Energy Corporation | Midland, TX 79701 | Oil & Gas Operator | Apr 1995 |
| 5 | Altamont Energy Operating LLC | Greenwood VIlliage, CO 80111 | Oil & Gas Operator | Sep 2024 |
| 6 | Ambra Oil & Gas Company | Rangely, CO 81648 | Oil & Gas Operator | Jul 2006 |
| 7 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 8 | Amtech Energy Inc | Plymouth, IL 62367-1016 | Oil & Gas Operator | Dec 2021 |
| 9 | Anr Limited Inc/Coastal | Houston, TX 770460995 | Oil & Gas Operator | Dec 1987 |
| 10 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 11 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 12 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 13 | Apc Operating Partnership | Tulsa, OK 74136 | Oil & Gas Operator | Oct 1996 |
| 14 | Arb Energy Utah, LLC | Katy, TX 77494 | Oil & Gas Operator | Jul 2025 |
| 15 | Arch Oil And Gas Company | Midland, TX 79702 | Oil & Gas Operator | Feb 1994 |
| 16 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 17 | Ashley Valley Operating Company LLC | Orem, UT 84097 | Oil & Gas Operator | Jun 2025 |
| 18 | Augustus Energy Partners LLC | Billings, MT 59102 | Oil & Gas Operator | Feb 2014 |
| 19 | Aviara Energy Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2002 |
| 20 | Axia Energy II LLC | HGHLNDS Ranch, CO 80129 | Oil & Gas Operator | Jan 2020 |
| 21 | Axia Energy LLC | Hghlands Ranch, CO 80129-2258 | Oil & Gas Operator | Jun 2016 |