| 1 | H & P Exploration Co. | Alice, TX 78333 | Oil & Gas Operator | May 2019 |
| 2 | H R E Rental Company | Premont, TX 78375 | Oil & Gas Operator | Sep 2015 |
| 3 | H-M Resource Management, Inc. | Houston, TX 77055 | Oil & Gas Operator | Feb 2023 |
| 4 | Haigood, Danny | Portland, TX 78374 | Oil & Gas Operator | Mar 2008 |
| 5 | Halcon Resources Operating, Inc. | Tulsa, OK 74135 | Oil & Gas Operator | Dec 2013 |
| 6 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 7 | Hamilton, J. R. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Jun 2025 |
| 8 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 9 | Hanson Minerals Co. | Houston, TX 77042 | Oil & Gas Operator | Oct 1993 |
| 10 | Hanson Production Company | Cuero, TX 77954 | Oil & Gas Operator | Jul 2009 |
| 11 | Hardwick, Mark P. Inc. | Midland, TX 79702 | Oil & Gas Operator | Nov 1994 |
| 12 | Harper Hefte, Inc. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Jun 2025 |
| 13 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | Jun 2025 |
| 14 | Harvey Brothers Oil & Gas | Corpus Chrsti, TX 78408 | Oil & Gas Operator | Jul 2004 |
| 15 | Harwood Exploration, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Aug 1995 |
| 16 | Hawk Exploration And Production | Corpus Chrsti, TX 78412 | Oil & Gas Operator | Oct 1995 |
| 17 | Hawk Petroleum, L L C | San Diego, TX 78384 | Oil & Gas Operator | Jun 2025 |
| 18 | Hawn Brothers | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2003 |
| 19 | Hawn Brothers Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jan 2003 |
| 20 | Hawthorn Energy Partners, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Jun 2025 |
| 21 | HBC Oil Company, LLC | San Antonio, TX 78266 | Oil Operator | Jun 2025 |
| 22 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 23 | Hep Oil Company LTD | Gainesville, TX 76240 | Oil & Gas Operator | Mar 2012 |
| 24 | Hep Oil GP, LLC | Gainesville, TX 76241 | Oil & Gas Operator | Mar 2015 |
| 25 | Hermat Salt Water Disposal, Inc. | Corpus Chrsti, TX 78426 | Oil Operator | Aug 2012 |
| 26 | Herschap Bros. | Bruni, TX 78344 | Oil & Gas Operator | Jun 2025 |
| 27 | High Sierra Operating, LTD. | Canyon Lake, TX 78133 | Oil & Gas Operator | Mar 2008 |
| 28 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Jun 2025 |
| 29 | Hinds Petroleum, LLC | Houston, TX 77263 | Oil Operator | Jun 2025 |
| 30 | Hinds Petroleum, LP | Houston, TX 77263 | Oil Operator | Feb 2017 |
| 31 | Holcomb Company, The | Freer, TX 78357 | Oil & Gas Operator | Aug 1996 |
| 32 | Hollimon Oil Corporation | Castroville, TX 78009 | Oil & Gas Operator | Nov 2016 |
| 33 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Jun 2025 |
| 34 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 35 | Howard Exploration, Inc. | Houston, TX 77069 | Oil & Gas Operator | Jun 2025 |
| 36 | Howard, Douglas J. | Houston, TX 77070 | Oil & Gas Operator | Mar 2008 |
| 37 | Howitzer Operating, LLC | Dallas, TX 75380 | Oil Operator | Jun 2025 |
| 38 | HRH Energy Group Incorporated | Carrollton, TX 75006 | Oil & Gas Operator | Nov 2009 |
| 39 | Huber Energy L.P. | Houston, TX 77079 | Oil & Gas Operator | Feb 2007 |
| 40 | Huber Energy Panhandle LP | Houston, TX 77079 | Oil & Gas Operator | Oct 2005 |
| 41 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Jun 2025 |
| 42 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 43 | Hughes, Dan A. Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | Jun 2025 |
| 44 | Hugoton Operating Company, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Jun 2025 |
| 45 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2025 |
| 46 | Hunter Petroleum Inc. | Alice, TX 78333 | Oil & Gas Operator | May 2014 |
| 47 | Hurd Enterprises, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | Jun 2025 |
| 48 | Hydrocarbon Operating, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jun 2025 |