| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | H. T. Hilliard & Co. | Oil & Gas Operator | Dec 1999 | |
| 2 | H. W. Reynolds Jr. | Gas Operator | Dec 1984 | |
| 3 | Hartley Natural Resource Development | Oil & Gas Operator | Aug 2024 | |
| 4 | Hexadyne Energy Corp. | Oil & Gas Operator | Dec 2013 |