| 1 | H & T Disposal | Abilene, TX 79608 | Oil Operator | Apr 2003 |
| 2 | H.A.N. Operating Incorporated | Clyde, TX 79510 | Oil & Gas Operator | Aug 2016 |
| 3 | Hallwood Energy Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2005 |
| 4 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 5 | Halvey Energy Co. | Midland, TX 79702 | Oil & Gas Operator | Oct 2004 |
| 6 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 7 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 8 | Harken Exploration Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2008 |
| 9 | Harvey, Mike W. Oil & Gas | Corpus Chrsti, TX 78408 | Oil & Gas Operator | Aug 2003 |
| 10 | Hastings, J. W. Oil Co. | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2010 |
| 11 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 12 | Hawkins Oil, L.L.C. | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 13 | Heart Land Petroleum Corporation | Abilene, TX 79604 | Oil & Gas Operator | Mar 2008 |
| 14 | Heights Energy Corporation | Plano, TX 75026 | Oil & Gas Operator | Oct 2025 |
| 15 | Hendrix, John H. Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2018 |
| 16 | Henson Exploration, L.P. | Abilene, TX 79608 | Oil & Gas Operator | Oct 2025 |
| 17 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Oct 2025 |
| 18 | HGN Operating Co. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2014 |
| 19 | HGN Operating I, LLC | Abilene, TX 79604 | Oil & Gas Operator | Oct 2025 |
| 20 | Hi - Mountain Energy Corporation | Odessa, TX 79762 | Oil & Gas Operator | Oct 2025 |
| 21 | Hickman-Jordan-Halligan Ranches | Blackwell, TX 79506 | Oil & Gas Operator | Feb 1998 |
| 22 | Highground, Inc. | Abilene, TX 79605 | Oil & Gas Operator | Oct 2025 |
| 23 | Hill, A G | Dallas, TX 75201 | Oil & Gas Operator | May 2008 |
| 24 | Hill, Albert, Trust | Dallas, TX 75201 | Oil & Gas Operator | May 2008 |
| 25 | Hofco, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Oct 2025 |
| 26 | Holden Oil & Gas | Abilene, TX 79608 | Oil & Gas Operator | Dec 2024 |
| 27 | Horizon Well Services, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Oct 2025 |
| 28 | Humphrey, Thos.D. Oil Prop.,Inc. | Gainesville, TX 76241 | Oil & Gas Operator | Aug 1999 |
| 29 | Humphrey-Bashford Oil, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Sep 2010 |
| 30 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 31 | Huntwood Resources, LLC | Huntsville, TX 77340 | Oil Operator | Oct 2025 |
| 32 | Hurst Oil & Gas, Inc. | Hillsboro, TX 76645 | Oil & Gas Operator | Dec 2024 |
| 33 | Hyquest Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Mar 2015 |