| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | H & N Operating Co., Inc. | Oil & Gas Operator | Oct 1997 | |
| 2 | Hayes & Assoc Inc | Oil & Gas Operator | Oct 1991 | |
| 3 | Herlihy John D. | Oil & Gas Operator | May 1997 | |
| 4 | Highmark Energy Operating LLC | Dallas, TX 75222 | Oil & Gas Operator | Dec 2025 |
| 5 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Dec 2025 |