| 1 | H & O Operating Co | Odessa, TX 79764 | Oil & Gas Operator | Mar 2008 |
| 2 | H.D. Smith, Inc. | Waller, TX 77484 | Oil Operator | Mar 2026 |
| 3 | Hadaway Consult And Engineer,LLC | Canadian, TX 79014 | Oil & Gas Operator | Sep 2026 |
| 4 | Hadson Energy Resources Corp. | Houston, TX 77056 | Oil & Gas Operator | Dec 1994 |
| 5 | Hampton Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Mar 1996 |
| 6 | Hanley Petroleum Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 7 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 8 | Hat Oil & Gas, Inc. | Slaton, TX 79364 | Oil & Gas Operator | Feb 2002 |
| 9 | Haylan Oil Company | Midland, TX 79710 | Oil & Gas Operator | Jan 2000 |
| 10 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 11 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 12 | Helms Oil & Gas, LLC | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 13 | Henderson, Bryan, Co. | Dallas, TX 75225 | Oil & Gas Operator | Sep 2026 |
| 14 | Hendrix, John H. Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2018 |
| 15 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 16 | Henry Petroleum LP | Midland, TX 79701 | Oil & Gas Operator | Dec 2008 |
| 17 | Henry Resources LLC | Midland, TX 79703 | Oil & Gas Operator | Sep 2026 |
| 18 | Herbig Oil & Gas Co. | Midland, TX 79705 | Oil & Gas Operator | Sep 2026 |
| 19 | Herbig, J F | Midland, TX 79701 | Oil & Gas Operator | Mar 1998 |
| 20 | Herricks Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Jan 2010 |
| 21 | Hibernia Resources III, LLC | Houston, TX 77056 | Oil & Gas Operator | Nov 2023 |
| 22 | Highland Production Company | Midland, TX 79701 | Oil & Gas Operator | Mar 1996 |
| 23 | Highmark Energy Operating, LLC | Houston, TX 77253 | Oil & Gas Operator | Sep 2026 |
| 24 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Sep 2026 |
| 25 | Hillin Prod. Co. | Odessa, TX 79760 | Oil & Gas Operator | Apr 2002 |
| 26 | Hillside Oil & Gas, LLC | Midland, TX 79708 | Oil & Gas Operator | Apr 2016 |
| 27 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 28 | Hog Partnership LP | Dallas, TX 75235 | Gas Operator | Jul 2026 |
| 29 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Sep 2026 |
| 30 | Honeck Oil Company | Austin, TX 78716 | Oil & Gas Operator | Mar 2008 |
| 31 | Honeck Oil Company, LP | Austin, TX 78716 | Oil & Gas Operator | Dec 2010 |
| 32 | Horizon Oil & Gas Co. | Dallas, TX 75221 | Oil & Gas Operator | Jan 2005 |
| 33 | HPPC, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2025 |
| 34 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Sep 2026 |
| 35 | Huff, Jack | Midland, TX 79710 | Oil & Gas Operator | Dec 2004 |
| 36 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2026 |
| 37 | Huntington Energy LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Sep 2026 |
| 38 | Hurst Oil & Gas, Inc. | Hillsboro, TX 76645 | Oil & Gas Operator | Dec 2024 |
| 39 | Hydrocarbon Management, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Dec 1996 |
| 40 | Hyquest Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Mar 2015 |