| 1 | Hansen Oil Corporation | Shreveport, LA 71106 | Oil Operator | Apr 2003 |
| 2 | Harleton Oil & Gas Inc. | Tyler, TX 75710 | Oil & Gas Operator | Oct 2025 |
| 3 | Harman Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Dec 2007 |
| 4 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Oct 2025 |
| 5 | Hibbard Energy, LP | Whitehouse, TX 75791 | Oil & Gas Operator | Oct 2025 |
| 6 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Oct 2025 |
| 7 | Hill, Hub, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jan 1994 |
| 8 | Hilliard Petroleum Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Sep 2009 |
| 9 | Hombre Oil Co., LTD. | Tyler, TX 75713 | Oil & Gas Operator | Apr 2021 |
| 10 | Hopewell Operating, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 11 | Howard, Anthony E. F. | Tyler, TX 75701 | Oil & Gas Operator | Jun 2001 |
| 12 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Oct 2025 |
| 13 | Hughey, W. R., Operating Co. | Tyler, TX 75711 | Oil & Gas Operator | Feb 2005 |
| 14 | Hugus Investment Company, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Oct 2025 |
| 15 | Humak Processors, Inc. | Tyler, TX 75710 | Oil & Gas Operator | Aug 2005 |
| 16 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 17 | Hunt Petroleum Corporation | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 18 | Hunt, WM. Herbert, Trust Est. | Dallas, TX 75201 | Oil & Gas Operator | Sep 1998 |
| 19 | Hydrogeo, L.L.C. | Houston, TX 77074 | Oil & Gas Operator | Oct 2025 |
| 20 | Hyperion Energy LP | Dallas, TX 75206 | Oil & Gas Operator | May 2014 |