| 1 | H & H Petroleum, LLC | San Antonio, TX 78213 | Oil Operator | May 2024 |
| 2 | H.L.S. Energy Co., Inc. | Uvalde, TX 78801 | Oil & Gas Operator | Aug 2003 |
| 3 | Haass Ranch Oil Company, LLC | Castroville, TX 78009 | Oil Operator | May 2024 |
| 4 | Hall Energy Company LLC | Oklahoma City, OK 73120-5020 | Oil & Gas Operator | Jul 2022 |
| 5 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2023 |
| 6 | Hanson Operating Company Inc | Roswell, NM 88202 | Oil & Gas Operator | Feb 2024 |
| 7 | Hardin, W.V. Estate | San Antonio, TX 78258 | Oil & Gas Operator | Apr 2002 |
| 8 | Harper Hefte, Inc. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | May 2024 |
| 9 | Hat Creek Energy LLC | Denver, CO 80209 | Oil & Gas Operator | Jun 2019 |
| 10 | Hawthorn Energy Partners, LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | May 2024 |
| 11 | HCM | Dallas, TX 75206 | Oil & Gas Operator | Mar 2015 |
| 12 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 13 | Hec Petroleum, Inc | Midland, TX 79705 | Oil & Gas Operator | Mar 2006 |
| 14 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 15 | Hinton Production Company | MT Pleasant, TX 75455 | Oil & Gas Operator | Aug 1995 |
| 16 | Holden Energy Corporation | Ardmore, OK 73401 | Oil & Gas Operator | Mar 2015 |
| 17 | Holley Oil Company, LLC | Chappell Hill, TX 77426 | Oil & Gas Operator | May 2024 |
| 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 | May 2024 |
| 21 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | May 2024 |
| 22 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 23 | Houston Oil & Gas Company, Inc. | Houston, TX 77063 | Oil & Gas Operator | Aug 1995 |
| 24 | Houston Petroleum Company | Houston, TX 77027 | Oil & Gas Operator | May 2024 |
| 25 | HPC Operating, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Mar 2008 |
| 26 | HRH Energy Group Incorporated | Carrollton, TX 75006 | Oil & Gas Operator | Nov 2009 |
| 27 | HS Resources, Inc. | Denver, CO 80202 | Oil & Gas Operator | Dec 2005 |
| 28 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 29 | Hughes, Dan A. Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | May 2024 |
| 30 | Hughey, W. R., Operating Co. | Tyler, TX 75711 | Oil & Gas Operator | Feb 2005 |
| 31 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | May 2024 |
| 32 | Hunter Petroleum Inc. | Alice, TX 78333 | Oil & Gas Operator | May 2014 |