| 1 | H & K Oil Company (A) | Luling, TX 78648 | Oil Operator | Apr 2026 |
| 2 | H. & J. Drilling Company | River Oaks, TX 76114 | Oil & Gas Operator | Aug 2003 |
| 3 | H.K.E. | Stafford, TX 77497 | Oil & Gas Operator | Apr 2026 |
| 4 | Hamilton, Clay | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Apr 2026 |
| 5 | Hankamer, Curtis Corporation,The | Houston, TX 77024 | Oil & Gas Operator | Apr 2026 |
| 6 | Hardin Energy Co., Inc. | Bigfoot, TX 78005 | Oil Operator | Apr 2026 |
| 7 | Hardin, W.V. Estate | San Antonio, TX 78258 | Oil & Gas Operator | Apr 2002 |
| 8 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 9 | Hawk Oil Co. | Luling, TX 78648 | Oil & Gas Operator | Aug 2003 |
| 10 | Hazelett Oil Company, Inc. | Dale, TX 78616 | Oil & Gas Operator | Sep 2005 |
| 11 | Hazelett Oil, Inc. | Dale, TX 78616 | Oil & Gas Operator | Aug 2024 |
| 12 | Herms, Walter | Luling, TX 78648 | Oil & Gas Operator | Sep 2002 |
| 13 | Hidden Oaks Oil Company, LLC | New Braunfels, TX 78132 | Oil Operator | Apr 2026 |
| 14 | Higginbotham, O. V. | Cedar Park, TX 78613 | Oil & Gas Operator | Jul 1996 |
| 15 | Higher Standard Oil Company,Inc. | Frisco, TX 75034 | Oil Operator | Apr 2026 |
| 16 | Holloway Oil Company | Austin, TX 78764 | Oil & Gas Operator | Feb 2004 |
| 17 | Hollub Production Company | Seguin, TX 78156 | Oil & Gas Operator | Jul 2000 |
| 18 | Hollub, Lambert Drilling Company | Seguin, TX 78155 | Oil & Gas Operator | Apr 2026 |
| 19 | Howell Drilling, Inc. | San Antonio, TX 78230 | Oil & Gas Operator | Aug 2003 |
| 20 | Hrbacek Oil Corp. | La Grange, TX 78945 | Oil & Gas Operator | Feb 2004 |