| 1 | H & S Production, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Mar 2004 |
| 2 | H & T Disposal | Abilene, TX 79608 | Oil Operator | Apr 2003 |
| 3 | H-S Exploration | Perryton, TX 79070 | Oil & Gas Operator | Oct 2025 |
| 4 | Hailey Energy Corporation | Wesson, MS 39191 | Gas Operator | May 2013 |
| 5 | Halliburton Operating Company | Plano, TX 75093 | Oil & Gas Operator | Oct 2025 |
| 6 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 7 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 8 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 9 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 10 | Harken Exploration Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2008 |
| 11 | HB Oil Company | Abilene, TX 79602 | Oil & Gas Operator | Jun 2023 |
| 12 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 13 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 14 | Heart Land Petroleum Corporation | Abilene, TX 79604 | Oil & Gas Operator | Mar 2008 |
| 15 | Henry, John Petroleum | Dallas, TX 75225 | Oil & Gas Operator | Dec 2001 |
| 16 | Henson Exploration, L.P. | Abilene, TX 79608 | Oil & Gas Operator | Oct 2025 |
| 17 | Hewitt, Alan P. | Midland, TX 79702 | Oil & Gas Operator | Aug 1997 |
| 18 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Oct 2025 |
| 19 | HGN Operating Co. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2014 |
| 20 | HGN Operating I, LLC | Abilene, TX 79604 | Oil & Gas Operator | Oct 2025 |
| 21 | Hickory Petroleum Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jun 2013 |
| 22 | Hillcrest Petroleum, LLC | Midland, TX 79707 | Oil & Gas Operator | Jun 2019 |
| 23 | Hodges & Hodges Productions | Anson, TX 79501 | Oil & Gas Operator | Aug 2003 |
| 24 | Hofco, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Oct 2025 |
| 25 | Holcomb Enterprises | Clyde, TX 79510 | Oil & Gas Operator | Aug 2003 |
| 26 | Holden Oil & Gas | Abilene, TX 79608 | Oil & Gas Operator | Dec 2024 |
| 27 | Holley Operating, L. L. C. | Abilene, TX 79601 | Oil Operator | Jul 2025 |
| 28 | Hood, J. F. | Holliday, TX 76366 | Oil & Gas Operator | Apr 2010 |
| 29 | Horizon Well Services, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Oct 2025 |
| 30 | Horn Energy | Eastland, TX 76448 | Oil & Gas Operator | Oct 2025 |
| 31 | Hovgard & Fitzgerald | Abilene, TX 79608 | Oil & Gas Operator | Mar 1996 |
| 32 | Hudgens Operating Co., Inc. | Abilene, TX 79603 | Oil & Gas Operator | Jul 1995 |
| 33 | Hughes, Bob Oil Company | San Angelo, TX 76901 | Oil & Gas Operator | Jul 2011 |
| 34 | Humphrey-Bashford Oil, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Sep 2010 |
| 35 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |