| 1 | Hadson Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 2 | Hall Edward L | Ada, OK 74820-3321 | Oil & Gas Operator | May 2025 |
| 3 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 4 | Hanna Oil And Gas Company | Fort Smith, AR 72901 | Oil & Gas Operator | Jun 2025 |
| 5 | Hart David | Chickasha, OK 73018-7756 | Oil & Gas Operator | Mar 2015 |
| 6 | HCG Energy Corporation & Subs | | Oil & Gas Operator | Mar 2015 |
| 7 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 8 | Headington Oil Company LLC | Dallas, TX 75204 | Oil & Gas Operator | Apr 2016 |
| 9 | Hogback Exploration Inc | Fort Smith, AR 72916 | Oil & Gas Operator | Jul 2025 |
| 10 | Hoover & Wilson Exp & Prod Inc | Fort Smith, AR 72913-5171 | Gas Operator | Jul 2013 |
| 11 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Oct 2024 |
| 12 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 13 | Howden Petroleum Corp | Wetumka, OK 74883 | Gas Operator | Nov 1997 |
| 14 | HRB Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2025 |
| 15 | HRC Production Co | Houston, TX 77024 | Oil & Gas Operator | May 2025 |
| 16 | Huitt Joe A | Tulsa, OK 74103 | Oil & Gas Operator | May 2001 |
| 17 | Huitt Joe A Rev Trust | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2009 |
| 18 | Hunt Energy Corporation | | Oil & Gas Operator | Feb 2002 |
| 19 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |