| 1 | Acco Oil & Gas Company | Houston, TX 77056 | Oil & Gas Operator | Sep 2001 |
| 2 | Acock Operating Limited | San Antonio, TX 78270 | Oil & Gas Operator | Apr 2024 |
| 3 | Acock/Anaqua Operating Co., LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2024 |
| 4 | Adobe Energy, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Nov 2004 |
| 5 | Aikman Oil Corp. | Oklahoma City, OK 73157 | Oil & Gas Operator | Apr 2024 |
| 6 | Akg Operating Company | Austin, TX 78701 | Oil & Gas Operator | Apr 2024 |
| 7 | Alamo Operating Company, L. C. | San Antonio, TX 78278 | Oil & Gas Operator | Aug 2023 |
| 8 | Alegre Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Apr 2024 |
| 9 | All Am, Inc. | Houston, TX 77057 | Oil & Gas Operator | Feb 2016 |
| 10 | Allegro Investments, Inc. | Victoria, TX 77903 | Oil & Gas Operator | Nov 2020 |
| 11 | Alpine Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 12 | Alta Mesa Services, LP | Houston, TX 77084 | Oil & Gas Operator | Apr 2024 |
| 13 | Alyana Energy Corporation | Houston, TX 77227 | Oil & Gas Operator | Apr 1995 |
| 14 | Amazon Royalties, Inc. | Fulshear, TX 77441 | Oil & Gas Operator | Apr 2024 |
| 15 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 16 | American Energy Partners Inc | Boerne, TX 78006 | Oil & Gas Operator | Dec 2011 |
| 17 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 18 | American Int'L Energy Corp. | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 19 | American Operating Company | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2003 |
| 20 | American Shoreline, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2024 |
| 21 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 22 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 23 | Apache Corporation | Houston, TX 77056 | Oil & Gas Operator | Apr 2024 |
| 24 | Arbol Resources, Inc. | Houston, TX 77079 | Oil & Gas Operator | Apr 2024 |
| 25 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 26 | Aries Operating LP | Houston, TX 77042 | Oil & Gas Operator | Apr 2024 |
| 27 | Arkla Exploration Co. | Shreveport, LA 71151 | Oil & Gas Operator | Jan 1993 |
| 28 | Arrowhead Enterprises, Inc. | Baton Rouge, LA 70816 | Oil & Gas Operator | Apr 2001 |
| 29 | Ashland Exploration Inc | Houston, TX 77218 | Oil & Gas Operator | Nov 2000 |
| 30 | Atapco | Houston, TX 77040 | Oil & Gas Operator | Feb 1999 |
| 31 | Atasca Resources Inc | Houston, TX 77219 | Oil & Gas Operator | Apr 2024 |
| 32 | Atropos Exploration Company | Dallas, TX 75225 | Oil & Gas Operator | Apr 2024 |
| 33 | Auburn Enterprises, Inc. | Kyle, TX 78640 | Oil & Gas Operator | Aug 2003 |
| 34 | Aurora Resources Corporation | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2024 |
| 35 | Axis Energy Corporation | Roswell, NM 88202 | Oil & Gas Operator | Apr 2024 |