| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | H. & N. Operating Co., Inc. | Oil & Gas Operator | Oct 1997 | |
| 2 | Harkins And Co., Et Al | Oil & Gas Operator | Dec 1980 | |
| 3 | Harrington Oil Inc. | Oil & Gas Operator | Apr 1978 | |
| 4 | Harrison Drilling Co | Oil & Gas Operator | Mar 1981 | |
| 5 | Hayes & Assoc Inc | Oil & Gas Operator | Oct 1991 | |
| 6 | Herlihy, John D. | Oil & Gas Operator | May 1997 | |
| 7 | Heron Operating, LLC | Oil & Gas Operator | Feb 2024 | |
| 8 | High Plains Operating Co | Oil & Gas Operator | Nov 1993 | |
| 9 | Hollingsworth & Assoc | Oil Operator | Feb 1987 | |
| 10 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 11 | Hughes & Hughes | Oil & Gas Operator | May 1984 | |
| 12 | Hughes & New Oil Co. | Oil Operator | Jul 1993 | |
| 13 | Hughes Eastern Corporation | Ridgeland, MS 39157 | Oil & Gas Operator | Dec 2023 |
| 14 | Humble Oil & Refining Co. | Houston, TX 77252 | Oil & Gas Operator | Jan 2000 |
| 15 | Huseman Oil International, Inc. | Oil & Gas Operator | Feb 1992 |