| 1 | H & O Operating Co | Odessa, TX 79764 | Oil & Gas Operator | Mar 2008 |
| 2 | Hadaway Consult And Engineer,LLC | Canadian, TX 79014 | Oil & Gas Operator | Jun 2025 |
| 3 | Halcon Operating Co., Inc. | Houston, TX 77024 | Oil & Gas Operator | Jun 2025 |
| 4 | Hallwood Petroleum, LLC | Dallas, TX 75219 | Oil & Gas Operator | Jan 2010 |
| 5 | Halvey Energy Co. | Midland, TX 79702 | Oil & Gas Operator | Oct 2004 |
| 6 | Hanley Petroleum Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 7 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 8 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 9 | Headington Oil Company, L.P. | Dallas, TX 75231 | Oil & Gas Operator | Mar 2008 |
| 10 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Feb 2025 |
| 11 | Henderson & Erickson, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 12 | Hendrix, John H. Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2018 |
| 13 | Henry Resources LLC | Midland, TX 79703 | Oil & Gas Operator | Jun 2025 |
| 14 | Hexp Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Jun 2025 |
| 15 | High Sky Oil & Gas | Midland, TX 79705 | Oil & Gas Operator | Jun 2008 |
| 16 | Highland Production Company | Midland, TX 79701 | Oil & Gas Operator | Mar 1996 |
| 17 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Jun 2025 |
| 18 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Jun 2025 |
| 19 | Hillin Prod. Co. | Odessa, TX 79760 | Oil & Gas Operator | Apr 2002 |
| 20 | Hillin, T. A. | Kerrville, TX 78028 | Oil & Gas Operator | Aug 2020 |
| 21 | Hopper, Harlan | Midland, TX 79702 | Oil & Gas Operator | Jun 2025 |
| 22 | Hopper, Thornton Co. | Midland, TX 79702 | Oil & Gas Operator | Jun 2025 |
| 23 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Oct 2024 |
| 24 | Horizon Oil & Gas Co. | Dallas, TX 75221 | Oil & Gas Operator | Jan 2005 |
| 25 | HPC Operating, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Mar 2008 |
| 26 | Huff, Jack | Midland, TX 79710 | Oil & Gas Operator | Dec 2004 |
| 27 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2025 |