| 1 | H. & N. Operating Co., Inc. | | Oil & Gas Operator | Oct 1997 |
| 2 | H. A. Harper | | Oil Operator | Dec 1982 |
| 3 | Hansen Oil Corporation | Shreveport, LA 71106 | Oil Operator | Apr 2003 |
| 4 | Hassie Hunt Expl. Company | Dallas, TX 75201 | Oil & Gas Operator | Aug 2008 |
| 5 | Hogan Exploration, Inc. | | Oil & Gas Operator | Mar 2000 |
| 6 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 7 | Hughes & Hughes | | Oil & Gas Operator | May 1984 |
| 8 | Hughes & New-D. Braswell | | Oil & Gas Operator | Jun 1983 |
| 9 | Hughes Denny Offshore Expl Inc | | Oil & Gas Operator | Nov 1988 |
| 10 | Hughes Eastern Corporation | Ridgeland, MS 39157 | Oil & Gas Operator | Dec 2023 |
| 11 | Hughes Eastern Petroleum, LTD. | | Oil & Gas Operator | Jun 1986 |
| 12 | Hughes-Denny Petroleum Co.,Inc | | Oil & Gas Operator | Dec 1987 |
| 13 | Hunt Oil Co., Et Al | | Oil & Gas Operator | Nov 1992 |
| 14 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Apr 2024 |
| 15 | Hurley Oil And Gas Company | | Oil & Gas Operator | Jan 1997 |
| 16 | Hyatt Exploration, Inc. | | Oil Operator | Jul 1995 |