| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Harkins & Co. | Oil & Gas Operator | Oct 1986 | |
| 2 | Highland Oil Co. | Oil Operator | Mar 1953 | |
| 3 | Houser, R. G. | Oil Operator | Mar 1953 | |
| 4 | Howell Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Oct 2015 |
| 5 | Hughes Petroleum Corp. | Oil Operator | Dec 1972 | |
| 6 | Humble Oil & Refining Co. | Houston, TX 77252 | Oil & Gas Operator | Jan 2000 |
| 7 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |