| 1 | H & T Oil & Gas Company, Inc. | Alice, TX 78333 | Oil & Gas Operator | Mar 2008 |
| 2 | H&K Energy | Stockdale, TX 78160 | Oil & Gas Operator | Jul 2005 |
| 3 | H. & J. Drilling Company | Fort Worth, TX 76114 | Oil & Gas Operator | Aug 2003 |
| 4 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 5 | Hardwick, Ross H. Oil Company | Devine, TX 78016 | Oil & Gas Operator | Mar 2025 |
| 6 | Harper Hefte, Inc. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Mar 2025 |
| 7 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 8 | Harvest Petroleum Inc. | Frisco, TX 75033 | Oil & Gas Operator | Mar 2025 |
| 9 | Harvey Brothers Oil & Gas | Corpus Chrsti, TX 78408 | Oil & Gas Operator | Jul 2004 |
| 10 | Harvey, Mike W. Oil & Gas | Corpus Chrsti, TX 78408 | Oil & Gas Operator | Aug 2003 |
| 11 | Hawthorn Energy Partners, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2025 |
| 12 | HCM | Dallas, TX 75206 | Oil & Gas Operator | Mar 2015 |
| 13 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 14 | Heartland Resources, Inc. | Temple, TX 76501 | Oil & Gas Operator | Mar 2008 |
| 15 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 16 | Hexp Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Mar 2025 |
| 17 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Mar 2025 |
| 18 | Hollimon Oil Corporation | Castroville, TX 78009 | Oil & Gas Operator | Nov 2016 |
| 19 | Holloway Oil Company | Austin, TX 78764 | Oil & Gas Operator | Feb 2004 |
| 20 | Hollub, Lambert Drilling Company | Seguin, TX 78155 | Oil & Gas Operator | Mar 2025 |
| 21 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Mar 2025 |
| 22 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 23 | Horizon Ridge Oil Company | Austin, TX 78738 | Oil Operator | Mar 2025 |
| 24 | Howard, Douglas J. | Houston, TX 77070 | Oil & Gas Operator | Mar 2008 |
| 25 | HRB Oil | Houston, TX 77042 | Oil & Gas Operator | Oct 1998 |
| 26 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 27 | Humedel Land & Minerals, Inc. | Jourdanton, TX 78026 | Oil & Gas Operator | Mar 2008 |
| 28 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Mar 2025 |
| 29 | Hunter Petroleum Inc. | Alice, TX 78333 | Oil & Gas Operator | May 2014 |
| 30 | Hunters Creek Oil & Gas | Houston, TX 77042 | Oil & Gas Operator | Mar 2025 |
| 31 | Huntington Energy LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2025 |