| 1 | H & L Operating Co., L.L.P. | Amarillo, TX 79114 | Oil & Gas Operator | Aug 2022 |
| 2 | H & L Operating Co., LLC | Amarillo, TX 79114 | Oil & Gas Operator | Mar 2021 |
| 3 | H & L Operating Company | Amarillo, TX 79114 | Oil & Gas Operator | Feb 2020 |
| 4 | H-S Exploration | Perryton, TX 79070 | Oil & Gas Operator | Oct 2025 |
| 5 | Hadaway Consult And Engineer,LLC | Canadian, TX 79014 | Oil & Gas Operator | Oct 2025 |
| 6 | Hadaway Engineering Inc | Canadian, TX 79014 | Oil & Gas Operator | Jul 2015 |
| 7 | Haider Operating, LLC | Pampa, TX 79066 | Oil & Gas Operator | Oct 2025 |
| 8 | Hall Energy Co. | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2016 |
| 9 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 10 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 11 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 12 | Hawthorn Energy Partners, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 13 | Hayabusa Energy USA, LLC | Pampa, TX 79065 | Oil & Gas Operator | Oct 2025 |
| 14 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jun 2025 |
| 15 | Hicks Exploration, LLC | Dover, OK 73734 | Gas Operator | Feb 2025 |
| 16 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Oct 2025 |
| 17 | Highmount Expl & Prod Texas LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2014 |
| 18 | Highmount Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2014 |
| 19 | Holmes Exploration, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2015 |
| 20 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Oct 2024 |
| 21 | Horizon Oil & Gas Co. | Dallas, TX 75221 | Oil & Gas Operator | Jan 2005 |
| 22 | HS Resources, Inc. | Denver, CO 80202 | Oil & Gas Operator | Dec 2005 |
| 23 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Oct 2025 |
| 24 | Hugoton Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2019 |
| 25 | Hydrocarbon Management, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Dec 1996 |