| 1 | H. & J. Drilling Company | Fort Worth, TX 76114 | Oil & Gas Operator | Aug 2003 |
| 2 | Haggard Operating Group/Oil | Atascosa, TX 78002 | Oil & Gas Operator | Oct 2025 |
| 3 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 4 | Hardwick, Ross H. Oil Company | Devine, TX 78016 | Oil & Gas Operator | Oct 2025 |
| 5 | Harmony Drilling Company, Inc. | Denver, CO 80222 | Oil & Gas Operator | Nov 2016 |
| 6 | Hereford, J. A. Industries, Inc. | Nacogdoches, TX 75961 | Oil & Gas Operator | Oct 2025 |
| 7 | Hollub, Lambert Drilling Company | Seguin, TX 78155 | Oil & Gas Operator | Oct 2025 |
| 8 | Hufo Production Corporation | Midland, TX 79702 | Oil & Gas Operator | Jul 2002 |
| 9 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |