| 1 | H & R Well Services, Inc. | FT Morgan, CO 80701 | Oil & Gas Operator | Apr 2015 |
| 2 | H. L. Hunt | | Oil & Gas Operator | Jun 1980 |
| 3 | Hardy Salt Co. | | Oil & Gas Operator | Apr 1986 |
| 4 | Headington Oil Company LLC | Dallas, TX 75204 | Oil & Gas Operator | Apr 2016 |
| 5 | Helis Oil & Gas Company, L.L.C. | New Orleans, LA 70130 | Oil & Gas Operator | Oct 2023 |
| 6 | Hess Bakken Investments II, LLC | | Oil & Gas Operator | Aug 2025 |
| 7 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 8 | High Plains Operating, LLC | | Oil Operator | Sep 2025 |
| 9 | Hilliard Oil & Gas Inc | New Orleans, LA 70112 | Oil & Gas Operator | May 2001 |
| 10 | HNG Oil Company | | Oil & Gas Operator | Jun 1987 |
| 11 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Oct 2025 |
| 12 | Houston Exploration Co, The | Houston, TX 77002 | Oil & Gas Operator | Apr 2017 |
| 13 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 14 | HRC Operating, LLC | Denver, CO 80202 | Oil & Gas Operator | Nov 2017 |
| 15 | Hunt Energy Corporation | | Oil & Gas Operator | Feb 2002 |
| 16 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 17 | Hunt Petroleum (Aec), Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 18 | Hunt Petroleum Corporation | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 19 | Huntford Resources Corp | Englewood, CO 80112 | Oil & Gas Operator | Nov 2001 |