| 1 | H & H Exploration | Tulsa, OK 74132 | Oil & Gas Operator | Jan 2006 |
| 2 | H & H Oil Productions | Tulsa, OK 74145 | Oil Operator | Jul 1999 |
| 3 | H.L.S. Energy Co., Inc. | Uvalde, TX 78801 | Oil & Gas Operator | Aug 2003 |
| 4 | Hadson Petro USA Inc | | Oil & Gas Operator | Nov 2016 |
| 5 | Hadson Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 6 | Halcon Holdings Inc | Ada, OK 74820 | Oil & Gas Operator | Feb 2026 |
| 7 | Hall Edward L | Ada, OK 74820-3321 | Oil & Gas Operator | Dec 2025 |
| 8 | Halliburton Oil Producing Co. | Duncan, OK 73534 | Oil & Gas Operator | Apr 2016 |
| 9 | Hamil Oil & Gas LLC | Kingfisher, OK 73750-6500 | Oil & Gas Operator | Feb 2026 |
| 10 | Hamon Jake L | Dallas, TX 75201-3902 | Oil & Gas Operator | Nov 1997 |
| 11 | Happy Hill Operating LLC | Guthrie, OK 73044-7361 | Oil & Gas Operator | Oct 2017 |
| 12 | Harbor Resources LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Jun 2026 |
| 13 | Harken Exploration Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2008 |
| 14 | Harrington Billy B | Depew, OK 74028-3495 | Oil & Gas Operator | May 2006 |
| 15 | Harrod Leasing | Edmond, OK 73034 | Oil & Gas Operator | Mar 2026 |
| 16 | Hazelwood Prod & Exp Co LLC | Oklahoma City, OK 73116-9037 | Oil & Gas Operator | Feb 2026 |
| 17 | Hazlewood Oil & Gas Co Inc | Oklahoma City, OK 73139-9353 | Oil & Gas Operator | Apr 2022 |
| 18 | Heartland Exploration | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2000 |
| 19 | Heartland Exploration Inc | Edmond, OK 73013 | Oil & Gas Operator | Dec 2015 |
| 20 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Feb 2026 |
| 21 | Henderson Fred J | Okmulgee, OK 74447 | Oil & Gas Operator | Jan 2026 |
| 22 | Hennessey Oil & Gas LLC | Hennessey, OK 73742-0212 | Oil & Gas Operator | Sep 2024 |
| 23 | Heritage Oil Company Inc | Norman, OK 73070 | Oil & Gas Operator | Jul 2008 |
| 24 | Heritage Petroleum, Inc. | Stillwater, OK 74076 | Oil & Gas Operator | Jun 2026 |
| 25 | Hewitt Energy Group Inc | Salt Lake City, UT 84111 | Oil & Gas Operator | Apr 2015 |
| 26 | High Energy | Cushing, OK 74023 | Oil & Gas Operator | Feb 2026 |
| 27 | Highland Minerals Inc | Tulsa, OK 74145-7627 | Oil & Gas Operator | Apr 2015 |
| 28 | Hightower Energy LLC | Cushing, OK 74023-6370 | Oil & Gas Operator | Feb 2026 |
| 29 | Hill Oil Company Inc | Shawnee, OK 74804 | Oil & Gas Operator | Feb 2026 |
| 30 | Hill Resources Inc | | Oil & Gas Operator | Nov 2022 |
| 31 | Himco Oil & Gas Inc | Enid, OK 73702 | Oil & Gas Operator | Feb 2026 |
| 32 | Hinkle Engineering, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Nov 2016 |
| 33 | Hinkle Oil And Gas Inc | Oklahoma City, OK 73112-4275 | Oil & Gas Operator | Mar 2026 |
| 34 | Hodgden Operating Co., Inc. | Enid, OK 73702 | Oil & Gas Operator | Mar 2026 |
| 35 | Hodge T F | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2007 |
| 36 | Holden Energy Corporation | Ardmore, OK 73401 | Oil & Gas Operator | Mar 2015 |
| 37 | Holke Dave Consulting Inc | Meridian, ID 83646-4812 | Oil & Gas Operator | Feb 2026 |
| 38 | Hollrah Exploration Company | Edmond, OK 73012 | Oil & Gas Operator | Feb 2026 |
| 39 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Oct 2024 |
| 40 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 41 | HRC Production Co | Houston, TX 77024 | Oil & Gas Operator | Mar 2026 |
| 42 | Hulen Operating Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Jun 2026 |
| 43 | Hungerford Oil & Gas Inc | Helena, OK 73741 | Oil & Gas Operator | Nov 2000 |
| 44 | Huntington Energy LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Jun 2026 |
| 45 | Hunton Oil & Gas Corporation | Oklahoma City, OK 73154-0191 | Oil & Gas Operator | May 2019 |
| 46 | Hunton Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2026 |
| 47 | Husky Ventures Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Feb 2026 |
| 48 | Hux Oil Company LLC | Kingfisher, OK 73750 | Oil & Gas Operator | Feb 2026 |
| 49 | Hyalite Energy Corporation | Pampa, TX 79066 | Oil & Gas Operator | Feb 2026 |