| 1 | H & O Operating Co | Odessa, TX 79764 | Oil & Gas Operator | Mar 2008 |
| 2 | H&P Oil & Gas LLC | Mertzon, TX 76941 | Oil & Gas Operator | Oct 2025 |
| 3 | H-M Resource Management, Inc. | Houston, TX 77055 | Oil & Gas Operator | Feb 2023 |
| 4 | Hallwood Energy Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2005 |
| 5 | Hannathon Petroleum, LLC | Midland, TX 79705 | Oil & Gas Operator | Oct 2025 |
| 6 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 7 | Harding Well Service Co. | Coahoma, TX 79511 | Oil & Gas Operator | Aug 2003 |
| 8 | Harvard Petroleum Corporation | Roswell, NM 88201 | Oil & Gas Operator | Dec 2004 |
| 9 | Henderson Natural Res, L.L.C. | Crozet, VA 22932 | Oil & Gas Operator | Oct 2025 |
| 10 | Henderson, Peter Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Feb 2020 |
| 11 | Hendrix, John H. Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2018 |
| 12 | Henry Petroleum LP | Midland, TX 79701 | Oil & Gas Operator | Dec 2008 |
| 13 | Henson Exploration, L.P. | Abilene, TX 79608 | Oil & Gas Operator | Oct 2025 |
| 14 | Herbig, J F | Midland, TX 79701 | Oil & Gas Operator | Mar 1998 |
| 15 | Hess, Jerry Operating Co. | Muenster, TX 76252 | Oil & Gas Operator | Oct 2025 |
| 16 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Oct 2025 |
| 17 | Hibernia Resources IV, LLC | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 18 | Hickox Oil Texas Company, Inc. | Mobile, AL 36689 | Oil & Gas Operator | Feb 1996 |
| 19 | Highland Production Company | Midland, TX 79701 | Oil & Gas Operator | Mar 1996 |
| 20 | Hillcrest Petroleum, LLC | Midland, TX 79707 | Oil & Gas Operator | Jun 2019 |
| 21 | Holler Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Aug 2003 |
| 22 | Holloway Oil Company | Austin, TX 78764 | Oil & Gas Operator | Feb 2004 |
| 23 | Holt Oil And Cattle LLC | Bedias, TX 77831 | Oil & Gas Operator | Oct 2025 |
| 24 | Horizon Well Services, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Oct 2025 |
| 25 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 26 | Hughes, Bob Oil Company | San Angelo, TX 76901 | Oil & Gas Operator | Jul 2011 |
| 27 | Hunt Petroleum Corporation | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 28 | HW Operating, LLC | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |