| 1 | H & H Drilling Company | Davis, OK 73030-2703 | Oil & Gas Operator | May 2014 |
| 2 | H & H Energy Inc | Tuttle, OK 73089 | Oil Operator | May 2001 |
| 3 | H2ok LLC | Marble Falls, TX 78654 | Oil & Gas Operator | Feb 2025 |
| 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 | Nov 2018 |
| 7 | Halliburton Oil Producing Co. | Duncan, OK 73534 | Oil & Gas Operator | Apr 2016 |
| 8 | Hammer Ranch | Elmore City, OK 73433 | Oil & Gas Operator | Jan 2023 |
| 9 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 10 | Hargraves Elston | Ponca City, OK 74604 | Oil & Gas Operator | Jul 2003 |
| 11 | Hargus Irrevocable Trust | Tecumseh, OK 74873-0590 | Oil Operator | Apr 2014 |
| 12 | Harris Minerals Corp (The) | Oklahoma City, OK 73162-1045 | Oil & Gas Operator | Jan 2025 |
| 13 | Harrison Oil | Lindsay, OK 73052 | Oil & Gas Operator | Nov 2014 |
| 14 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 15 | Hazlewood Oil & Gas Co Inc | Oklahoma City, OK 73139-9353 | Oil & Gas Operator | Apr 2022 |
| 16 | HCG Energy Corporation & Subs | | Oil & Gas Operator | Mar 2015 |
| 17 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 18 | Headington Oil Company LLC | Dallas, TX 75204 | Oil & Gas Operator | Apr 2016 |
| 19 | Heartland Exploration Inc | Edmond, OK 73013 | Oil & Gas Operator | Dec 2015 |
| 20 | Heath Oil Co., Inc. | Washington, OK 73093-4702 | Oil & Gas Operator | Jan 2025 |
| 21 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jan 2025 |
| 22 | Hemstead Oil Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2001 |
| 23 | Henderson Fred J | Okmulgee, OK 74447-9204 | Oil & Gas Operator | Jan 2025 |
| 24 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 25 | Highland Energy Co | Dallas, TX 75201 | Oil & Gas Operator | Jun 1994 |
| 26 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Apr 2025 |
| 27 | Hilliard Oil & Gas Inc | New Orleans, LA 70112 | Oil & Gas Operator | May 2001 |
| 28 | Hilligoss Leonard | | Oil Operator | Aug 2022 |
| 29 | Hillin-Simon Oil Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2013 |
| 30 | Hinkle Engineering, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Nov 2016 |
| 31 | Hinkle Oil And Gas Inc | Oklahoma City, OK 73112-4275 | Oil & Gas Operator | Feb 2025 |
| 32 | Hoard John L Family Trust | Ardmore, OK 73402-1706 | Oil & Gas Operator | Jun 2022 |
| 33 | Hoco Inc | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2025 |
| 34 | Hodgden Operating Co., Inc. | Enid, OK 73702 | Oil & Gas Operator | Feb 2025 |
| 35 | Hoke Jr J T | Edmond, OK 73034 | Oil Operator | Nov 1998 |
| 36 | Holden Energy Corporation | Ardmore, OK 73401 | Oil & Gas Operator | Mar 2015 |
| 37 | Hollrah Exploration Company | Oklahoma City, OK 73142 | Oil & Gas Operator | Feb 2025 |
| 38 | Hondo Oil & Gas Company | Roswell, NM 88202 | Oil & Gas Operator | Aug 2006 |
| 39 | Hooks Dwain | Tatums, OK 73487 | Oil & Gas Operator | Oct 2024 |
| 40 | Horton Mary | Ratliff City, OK 73481 | Oil Operator | May 2020 |
| 41 | Howard & Taylor | Wynnewood, OK 73098-9234 | Oil & Gas Operator | Jan 2025 |
| 42 | HRC Production Co | Houston, TX 77002 | Oil & Gas Operator | Jan 2025 |
| 43 | Huck Farms LLC | Stratford, OK 74872 | Oil & Gas Operator | Jan 2025 |
| 44 | Hunt Engineering Inc | Norman, OK 73069-4093 | Oil & Gas Operator | Feb 2019 |
| 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 2025 |
| 47 | Hux Oil Company LLC | Kingfisher, OK 73750 | Oil & Gas Operator | Jan 2025 |
| 48 | Hylmn LLC | Wills Point, TX 75169 | Oil Operator | Jun 2022 |
| 49 | Hyperion Oil & Gas LLC | Dallas, TX 75251 | Oil & Gas Operator | Apr 2025 |