| 1 | H2ox Operating LLC | | Oil Operator | Feb 2024 |
| 2 | Hadson Petro USA Inc | | Oil & Gas Operator | Nov 2016 |
| 3 | Halcon Holdings Inc | Ada, OK 74820 | Oil & Gas Operator | Nov 2018 |
| 4 | Ham Oil Company, LLC | | Oil Operator | Sep 2022 |
| 5 | Hamil Oil & Gas LLC | | Oil & Gas Operator | Jan 2024 |
| 6 | Hammer Oil Properties Inc | Enid, OK 73706-0144 | Oil & Gas Operator | Oct 2017 |
| 7 | Harbor Resources LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Apr 2024 |
| 8 | Hartman Oil Company Inc | Wichita, KS 67206 | Oil & Gas Operator | Dec 2023 |
| 9 | Hazelwood Prod & Exp Co LLC | Oklahoma City, OK 73116-9037 | Oil & Gas Operator | Dec 2023 |
| 10 | Hazlewood Oil & Gas Co Inc | Oklahoma City, OK 73139-9353 | Oil & Gas Operator | Apr 2022 |
| 11 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 12 | Heartland Exploration | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2000 |
| 13 | Heartlands Development Co Inc | Bristow, OK 74010-3826 | Oil & Gas Operator | May 2017 |
| 14 | Helena Resources LLC | Helena, OK 73741-4120 | Oil & Gas Operator | Jan 2024 |
| 15 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jan 2024 |
| 16 | Hennessey Oil & Gas LLC | Hennessey, OK 73742-0212 | Oil & Gas Operator | Jan 2024 |
| 17 | Henry Gungoll Operating Inc | Enid, OK 73702-6209 | Oil & Gas Operator | Feb 2024 |
| 18 | Heritage Petroleum, Inc. | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2024 |
| 19 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 20 | High Energy | Cushing, OK 74023-1762 | Oil & Gas Operator | Jan 2024 |
| 21 | High Sierra Crude Oil& Marketing LLC | Ardmore, OK 73401 | Oil Operator | Nov 2013 |
| 22 | Hill Resources Inc | | Oil & Gas Operator | Nov 2022 |
| 23 | Himco Oil & Gas, Inc. | Enid, OK 73702 | Oil & Gas Operator | Jan 2024 |
| 24 | Hinkle Engineering, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Nov 2016 |
| 25 | Hinkle Oil And Gas Inc | Oklahoma City, OK 73112-4275 | Oil & Gas Operator | Feb 2024 |
| 26 | Hodgden Operating Co., Inc. | Enid, OK 73702 | Oil & Gas Operator | Feb 2024 |
| 27 | Hoehn French | Enid, OK 73701-5600 | Oil & Gas Operator | Oct 1996 |
| 28 | Holden Energy Corporation | Ardmore, OK 73401 | Oil & Gas Operator | Mar 2015 |
| 29 | Hondo Oil & Gas Company | Roswell, NM 88202 | Oil & Gas Operator | Aug 2006 |
| 30 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Jan 2024 |
| 31 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 32 | Hungerford Oil & Gas Inc | Helena, OK 73741 | Oil & Gas Operator | Nov 2000 |
| 33 | Hunt Engineering Inc | Norman, OK 73069-4093 | Oil & Gas Operator | Feb 2019 |
| 34 | Hux Oil Company LLC | Kingfisher, OK 73750-0474 | Oil & Gas Operator | Jan 2024 |
| 35 | Hy-Carb Energy Inc | | Oil & Gas Operator | Feb 2009 |