| 1 | Hallwood Energy Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2005 |
| 2 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2023 |
| 3 | Halvey Energy Co. | Midland, TX 79702 | Oil & Gas Operator | Oct 2004 |
| 4 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Apr 2024 |
| 5 | Hanley Petroleum Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 6 | Hanson Operating Company Inc | Roswell, NM 88202 | Oil & Gas Operator | Jan 2024 |
| 7 | Hat Oil & Gas, Inc. | Slaton, TX 79364 | Oil & Gas Operator | Feb 2002 |
| 8 | Headington Energy Partners, LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2024 |
| 9 | Hec Petroleum, Inc | Midland, TX 79705 | Oil & Gas Operator | Mar 2006 |
| 10 | Helms Oil & Gas, LLC | Midland, TX 79710 | Oil & Gas Operator | Apr 2024 |
| 11 | Henderson & Erickson, Inc. | Midland, TX 79701 | Oil & Gas Operator | Apr 2024 |
| 12 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 13 | Henry Petroleum LP | Midland, TX 79701 | Oil & Gas Operator | Dec 2008 |
| 14 | Henry Resources LLC | Midland, TX 79703 | Oil & Gas Operator | Apr 2024 |
| 15 | Heritage Resources, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Feb 2014 |
| 16 | Heritage Standard Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2024 |
| 17 | Herricks Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Jan 2010 |
| 18 | Hexp Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Apr 2024 |
| 19 | High Sky Partners LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2015 |
| 20 | Hillin Prod. Co. | Odessa, TX 79760 | Oil & Gas Operator | Apr 2002 |
| 21 | Hillside Oil & Gas, LLC | Midland, TX 79708 | Oil & Gas Operator | Apr 2016 |
| 22 | Holliday Drilling, Inc. | Stephenville, TX 76401 | Oil & Gas Operator | Dec 2020 |
| 23 | Holly Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Nov 2008 |
| 24 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 25 | HPPC, Inc. | Midland, TX 79701 | Oil & Gas Operator | Feb 2023 |
| 26 | Hulsey Larry O & Co | Graham, TX 76046 | Oil & Gas Operator | Jun 2012 |
| 27 | Humble Oil & Refining Co. | Houston, TX 77252 | Oil & Gas Operator | Jan 2000 |
| 28 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Apr 2024 |
| 29 | Hurst Oil & Gas, Inc. | Hillsboro, TX 76645 | Oil & Gas Operator | Apr 2024 |