| 1 | Haas, C. F. Oil & Gas Inc. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Mar 2025 |
| 2 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Mar 2025 |
| 3 | Hankey Oil Company | Houston, TX 77027 | Oil & Gas Operator | Feb 2010 |
| 4 | Hankey Operating, Inc. | Houston, TX 77027 | Oil & Gas Operator | Mar 2016 |
| 5 | Hanson Minerals Co. | Houston, TX 77042 | Oil & Gas Operator | Oct 1993 |
| 6 | Hanson Production Company | Cuero, TX 77954 | Oil & Gas Operator | Jul 2009 |
| 7 | Hawn Brothers | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2003 |
| 8 | Hayes Oil & Gas Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2005 |
| 9 | Headington Energy Partners, LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2025 |
| 10 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 11 | Headington Oil Company LLC | Dallas, TX 75204 | Oil & Gas Operator | Apr 2016 |
| 12 | Headington Oil Company, L.P. | Dallas, TX 75231 | Oil & Gas Operator | Mar 2008 |
| 13 | Herschap Bros. | Bruni, TX 78344 | Oil & Gas Operator | Mar 2025 |
| 14 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Mar 2025 |
| 15 | Holbein & Wright Resources Inc. | Bandera, TX 78003 | Oil & Gas Operator | Mar 2025 |
| 16 | Holloway Oil Company | Austin, TX 78764 | Oil & Gas Operator | Feb 2004 |
| 17 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Mar 2025 |
| 18 | Houston Exploration Co, The | Houston, TX 77002 | Oil & Gas Operator | Apr 2017 |
| 19 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 20 | Howard Exploration, Inc. | Houston, TX 77069 | Oil & Gas Operator | Mar 2025 |
| 21 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 22 | Hughes, Dan A. Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | Mar 2025 |
| 23 | Hugoton Operating Company, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Mar 2025 |
| 24 | Hurd Enterprises, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2025 |
| 25 | Hydrocarbon Operating, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2025 |