| 1 | Halcon Operating Co., Inc. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 2 | Halcon Resources Operating, Inc. | Tulsa, OK 74135 | Oil & Gas Operator | Dec 2013 |
| 3 | Hall Exploration, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 4 | Hallwood Energy Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2005 |
| 5 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 6 | Hanger Oil, L.L.C. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 7 | Hanley Petroleum Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 8 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 9 | Hanvey, Don H. Oil Interests Inc | Cisco, TX 76437 | Oil & Gas Operator | Oct 2025 |
| 10 | Hardwick, Mark P. Inc. | Midland, TX 79702 | Oil & Gas Operator | Nov 1994 |
| 11 | Harkey Energy Inc. | Odessa, TX 79762 | Oil & Gas Operator | Feb 2020 |
| 12 | Harleton Oil & Gas Inc. | Tyler, TX 75710 | Oil & Gas Operator | Oct 2025 |
| 13 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 14 | Hec Petroleum, Inc | Midland, TX 79705 | Oil & Gas Operator | Mar 2006 |
| 15 | Heifer Production Company LLC | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 16 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jun 2025 |
| 17 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 18 | Henry Resources LLC | Midland, TX 79703 | Oil & Gas Operator | Oct 2025 |
| 19 | Heritage Resources, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Feb 2014 |
| 20 | Heritage Standard Corporation | Dallas, TX 75206 | Oil & Gas Operator | Oct 2025 |
| 21 | Herricks Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Jan 2010 |
| 22 | High Desert Resources, L.L.C. | Midland, TX 79704 | Oil Operator | Oct 2025 |
| 23 | Highland Production Company | Midland, TX 79701 | Oil & Gas Operator | Mar 1996 |
| 24 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Oct 2025 |
| 25 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Oct 2025 |
| 26 | Hillin Prod. Co. | Odessa, TX 79760 | Oil & Gas Operator | Apr 2002 |
| 27 | Hillin-Simon Oil Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2013 |
| 28 | Hillside Oil & Gas, LLC | Midland, TX 79708 | Oil & Gas Operator | Apr 2016 |
| 29 | HMH Operators, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 30 | Hopewell Operating, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 31 | Huff, Jack | Midland, TX 79710 | Oil & Gas Operator | Dec 2004 |
| 32 | Hulsey Oil Company | Dallas, TX 75205 | Oil & Gas Operator | Aug 1999 |
| 33 | Hurst Oil & Gas, Inc. | Hillsboro, TX 76645 | Oil & Gas Operator | Dec 2024 |