| 1 | H & O Operating Co | Odessa, TX 79764 | Oil & Gas Operator | Mar 2008 |
| 2 | H&M Production, Inc. | New Braunfels, TX 78132 | Oil & Gas Operator | Aug 2012 |
| 3 | H. & L. Oil Company | Midland, TX 79707 | Oil & Gas Operator | Mar 2005 |
| 4 | Habanero Oil & Gas Operating,LLC | Austin, TX 78701 | Oil & Gas Operator | Feb 2018 |
| 5 | Halcon Operating Co., Inc. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 6 | Hamm, Richard Inc. | Monahans, TX 79756 | Oil & Gas Operator | Oct 2025 |
| 7 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 8 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 9 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 10 | Hanvey, Don H. Oil Interests Inc | Cisco, TX 76437 | Oil & Gas Operator | Oct 2025 |
| 11 | Harkey Energy Inc. | Odessa, TX 79762 | Oil & Gas Operator | Feb 2020 |
| 12 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 13 | Haylan Oil Company | Midland, TX 79710 | Oil & Gas Operator | Jan 2000 |
| 14 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 15 | Headington Oil Company, L.P. | Dallas, TX 75231 | Oil & Gas Operator | Mar 2008 |
| 16 | Heifer Production Company LLC | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 17 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jun 2025 |
| 18 | Hendrix, John H. Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2018 |
| 19 | Henry Resources LLC | Midland, TX 79703 | Oil & Gas Operator | Oct 2025 |
| 20 | Henson Exploration, L.P. | Abilene, TX 79608 | Oil & Gas Operator | Oct 2025 |
| 21 | Herricks Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Jan 2010 |
| 22 | Hewitt, Alan P. | Midland, TX 79702 | Oil & Gas Operator | Aug 1997 |
| 23 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Oct 2025 |
| 24 | Hi - Mountain Energy Corporation | Odessa, TX 79762 | Oil & Gas Operator | Oct 2025 |
| 25 | Hicon Gas Producers, Inc. | New York, NY 10110 | Oil & Gas Operator | Oct 1999 |
| 26 | High Mountain Oil & Gas | Hobbs, NM 88240 | Oil & Gas Operator | Jan 2019 |
| 27 | High Mountain Oil & Gas, LLC | Hobbs, NM 88240 | Oil & Gas Operator | Oct 2025 |
| 28 | Highland Production Company | Midland, TX 79701 | Oil & Gas Operator | Mar 1996 |
| 29 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Oct 2025 |
| 30 | Hill, A G | Dallas, TX 75201 | Oil & Gas Operator | May 2008 |
| 31 | Hillin Prod. Co. | Odessa, TX 79760 | Oil & Gas Operator | Apr 2002 |
| 32 | Hillin Simon/Prime Expl., L.C. | Midland, TX 79702 | Oil & Gas Operator | Jun 2000 |
| 33 | Hillin, T. A. | Kerrville, TX 78028 | Oil & Gas Operator | Aug 2020 |
| 34 | Hillin-Simon Oil Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2013 |
| 35 | Hillside Oil & Gas, LLC | Midland, TX 79708 | Oil & Gas Operator | Apr 2016 |
| 36 | Hinkle Engineering, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Nov 2016 |
| 37 | HMH Operators, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 38 | Holly Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Nov 2008 |
| 39 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Oct 2025 |
| 40 | Horizon Ridge Oil Company | Austin, TX 78738 | Oil Operator | Oct 2025 |
| 41 | Houghton Oil & Gas, Inc. | Midland, TX 79701 | Oil & Gas Operator | Mar 2009 |
| 42 | Howell Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Oct 2015 |
| 43 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Oct 2025 |
| 44 | Hudson, Comer Oil & Gas | Cisco, TX 76437 | Oil & Gas Operator | Jan 2003 |
| 45 | Hulsey Larry O & Co | Graham, TX 76046 | Oil & Gas Operator | Jun 2012 |
| 46 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 47 | Hunt, Hassie Exploration Company | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 48 | Huntington Energy LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 49 | Hybrid Operating, Incorporated | Carlsbad, CA 92009 | Oil & Gas Operator | Oct 2025 |
| 50 | Hydrogeo, L.L.C. | Houston, TX 77074 | Oil & Gas Operator | Oct 2025 |