| 1 | A. J. Hayes | | Oil & Gas Operator | Dec 1998 |
| 2 | A. L. & V. I. Grayson | | Oil Operator | Dec 1993 |
| 3 | A. S. Johnston Drilling Corp. | | Oil & Gas Operator | Dec 1987 |
| 4 | A.L.S. Resources Inc. | | Oil Operator | Dec 2004 |
| 5 | Aa Production Services Inc. | | Gas Operator | Dec 2025 |
| 6 | Aalpha Energy Inc. | | Oil & Gas Operator | Mar 2026 |
| 7 | Aba Energy Corporation | | Oil & Gas Operator | Mar 2026 |
| 8 | ABC Oil Company Inc | Wichita Falls, TX 76301 | Oil & Gas Operator | Oct 2023 |
| 9 | Adco LTD. | | Oil & Gas Operator | Dec 1983 |
| 10 | Aera Energy LLC | | Oil & Gas Operator | Mar 2026 |
| 11 | Agey Petroleum Co. | | Oil & Gas Operator | Dec 1998 |
| 12 | Alanmar Energy | | Gas Operator | Jan 2018 |
| 13 | Alexander Oil Company | Loco, OK 73442-9409 | Oil & Gas Operator | Feb 2026 |
| 14 | Allenco Energy Inc. | | Oil & Gas Operator | Dec 2025 |
| 15 | Allied Energy Corporation | | Oil & Gas Operator | Dec 2025 |
| 16 | Allied Western Petroleum | | Oil & Gas Operator | Dec 2025 |
| 17 | Almond Crest Oil LLC | | Oil & Gas Operator | Dec 2025 |
| 18 | Amerada Hess Corp. Unit Operator | | Oil & Gas Operator | Dec 1986 |
| 19 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 20 | American Barter Petroleum Inc. | | Oil & Gas Operator | Jun 1993 |
| 21 | Ample Resources Inc. | | Oil & Gas Operator | Dec 2025 |
| 22 | Amrich Energy Inc. | | Oil & Gas Operator | Dec 2025 |
| 23 | Anacapa Oil Corporation | | Gas Operator | Dec 2025 |
| 24 | Anadime Energy Services Inc. | | Oil & Gas Operator | Dec 2009 |
| 25 | Ancora-Verde Corporation | | Oil & Gas Operator | Dec 2004 |
| 26 | Andrew L. Newkirk | | Oil Operator | Dec 2025 |
| 27 | Angus Petroleum Corporation | Chicago, IL 60660 | Oil & Gas Operator | Dec 2022 |
| 28 | Ann Brindle | | Oil Operator | Mar 2026 |
| 29 | Ann Marie Tiers | | Oil Operator | Dec 1996 |
| 30 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2026 |
| 31 | Anterra Energy Services Inc. | | Oil & Gas Operator | Dec 2025 |
| 32 | Anterra Services Inc. | | Oil & Gas Operator | Dec 2025 |
| 33 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | May 2026 |
| 34 | Apc Operating Partnership | Tulsa, OK 74136 | Oil & Gas Operator | Oct 1996 |
| 35 | Arcady Oil Company | | Gas Operator | Dec 1989 |
| 36 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 37 | Arco Western Energy Co. | | Oil & Gas Operator | Dec 1999 |
| 38 | Argo Petroleum Corporation | | Oil & Gas Operator | Dec 1989 |
| 39 | Argosy Oil Company | | Gas Operator | Dec 1999 |
| 40 | Aristata Exploration Co. | | Gas Operator | Dec 2009 |
| 41 | Arkoma Production Company Of California | | Oil & Gas Operator | Dec 1993 |
| 42 | Armca Oil & Gas LLC | | Oil Operator | Mar 2026 |
| 43 | Armstrong Oil Inc. | | Oil & Gas Operator | Dec 2020 |
| 44 | Armstrong Petroleum Corporation | | Oil & Gas Operator | Dec 2025 |
| 45 | Arrowhead Operating Inc. | Argyle, TX 76226 | Oil & Gas Operator | May 2026 |
| 46 | Arthur J. Arding Jr. | | Gas Operator | Dec 1995 |
| 47 | Arthur McAdams | | Oil & Gas Operator | Dec 2025 |
| 48 | Ashe Road Properties L.P. | | Oil & Gas Operator | Dec 2009 |
| 49 | Asioco Inc. | | Oil & Gas Operator | Jan 2018 |
| 50 | Aspen Exploration Corporation | | Oil & Gas Operator | Dec 2007 |
| 51 | Asphalta LLC | | Oil & Gas Operator | Mar 2026 |
| 52 | Astarta Springs Sustainable Farms LLC | | Oil & Gas Operator | Dec 2025 |
| 53 | Atasca Resources, Inc. | Houston, TX 77219 | Oil & Gas Operator | May 2026 |
| 54 | Atlantic Oil Company | | Oil & Gas Operator | Dec 2025 |
| 55 | Atlantic Richfield Company | Houston, TX 77079 | Oil & Gas Operator | Dec 2016 |
| 56 | Austin Oil Company | | Oil & Gas Operator | Dec 2000 |
| 57 | Axis Petroleum Co. | | Oil & Gas Operator | Dec 2022 |