| 1 | H & S Production, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Mar 2004 |
| 2 | Hardey Co., The | Shreveport, LA 71107 | Oil & Gas Operator | Oct 2025 |
| 3 | Harleton Oil & Gas Inc. | Tyler, TX 75710 | Oil & Gas Operator | Oct 2025 |
| 4 | Hawkeye Drilling Co. | Waskom, TX 75692 | Oil & Gas Operator | Feb 2023 |
| 5 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 6 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 7 | Hennan Resources, Inc. | Great Neck, NY 11021 | Gas Operator | Nov 1997 |
| 8 | Hep Oil GP, LLC | Gainesville, TX 76241 | Oil & Gas Operator | Mar 2015 |
| 9 | Hibbard Energy, LP | Whitehouse, TX 75791 | Oil & Gas Operator | Oct 2025 |
| 10 | Hightower Exploration | Kilgore, TX 75662 | Oil & Gas Operator | Oct 2025 |
| 11 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Oct 2025 |
| 12 | Hill Production Company | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2009 |
| 13 | Hoell Operating, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 14 | Hooper & Sons Investments Co.Inc | Tenaha, TX 75974 | Gas Operator | Nov 1997 |
| 15 | Hopewell Operating, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 16 | Hopkins, T. M. Operating Co. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 17 | Howell Oil & Gas, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Oct 2019 |
| 18 | HPC Operating, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Mar 2008 |
| 19 | HRB Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2025 |
| 20 | Huggs Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Apr 2003 |
| 21 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 22 | Hunt Petroleum Corporation | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 23 | Hunt, WM. Herbert, Trust Est. | Dallas, TX 75201 | Oil & Gas Operator | Sep 1998 |
| 24 | Hurley Petroleum Corporation | Baton Rouge, LA 70821 | Oil & Gas Operator | Feb 2000 |
| 25 | Hydrocarbon Lease Management LTD | Addison, TX 75001 | Oil & Gas Operator | Jul 2002 |