| 1 | H & L Exploration Company, LLC | Amarillo, TX 79114 | Oil & Gas Operator | Oct 2025 |
| 2 | H & L Operating Co., L.L.P. | Amarillo, TX 79114 | Oil & Gas Operator | Aug 2022 |
| 3 | H & L Operating Co., LLC | Amarillo, TX 79114 | Oil & Gas Operator | Mar 2021 |
| 4 | H & L Operating Company | Amarillo, TX 79114 | Oil & Gas Operator | Feb 2020 |
| 5 | H-S Exploration | Perryton, TX 79070 | Oil & Gas Operator | Oct 2025 |
| 6 | Haider Operating, LLC | Pampa, TX 79066 | Oil & Gas Operator | Oct 2025 |
| 7 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 8 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 9 | Harken Exploration Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2008 |
| 10 | Harmon, C. E. Oil, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Oct 2019 |
| 11 | Harris Oil & Gas Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2016 |
| 12 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 13 | Herrmann, J.B. | Amarillo, TX 79159 | Oil & Gas Operator | Aug 2019 |
| 14 | Herrmann, S. W. Oil & Gas | Amarillo, TX 79159 | Oil & Gas Operator | Oct 2025 |
| 15 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Oct 2025 |
| 16 | Hicks Exploration, LLC | Dover, OK 73734 | Gas Operator | Feb 2025 |
| 17 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Oct 2025 |
| 18 | Holt Brothers | Gruver, TX 79040 | Gas Operator | Oct 2025 |
| 19 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Oct 2024 |
| 20 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 21 | Horizon Oil & Gas Co. | Dallas, TX 75221 | Oil & Gas Operator | Jan 2005 |
| 22 | HRB Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2025 |
| 23 | HS Resources, Inc. | Denver, CO 80202 | Oil & Gas Operator | Dec 2005 |
| 24 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Oct 2025 |
| 25 | Hugoton Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2019 |
| 26 | Hunter Oil Corporation | Gruver, TX 79040 | Gas Operator | Oct 2025 |
| 27 | Huntington Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2006 |
| 28 | Hy-Tech, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Feb 2017 |