| 1 | W. H. Hunt Trust Estate | | Oil & Gas Operator | Mar 1997 |
| 2 | Wacker Oil Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 3 | Wapiti Operating, LLC | Houston, TX 77043 | Oil & Gas Operator | Nov 2024 |
| 4 | Ward-Williston Company | | Oil & Gas Operator | Apr 2014 |
| 5 | Ward-Williston Drilling Co. | | Oil & Gas Operator | Dec 1994 |
| 6 | Wesco Operating, Inc. | Casper, WY 82602 | Oil & Gas Operator | Sep 2024 |
| 7 | Wessely Energy Company | Dallas, TX 75206 | Oil & Gas Operator | May 2001 |
| 8 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 9 | White Butte Oil Operations, LLC | | Oil & Gas Operator | Sep 2024 |
| 10 | White Rock Oil & Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | Nov 2024 |
| 11 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Nov 2024 |
| 12 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jul 2024 |
| 13 | William Herbert Hunt | | Oil & Gas Operator | Mar 1986 |
| 14 | Williston Hunter ND, LLC | | Oil & Gas Operator | Mar 2014 |
| 15 | Williston Industrial Supply Corporation | Williston, ND 58801 | Oil & Gas Operator | Mar 2012 |
| 16 | Windridge Operating LLC | | Oil & Gas Operator | Sep 2024 |
| 17 | Windsor Energy Group LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Aug 2021 |
| 18 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 19 | WPX Energy Williston, LLC | | Oil & Gas Operator | Sep 2024 |
| 20 | Wyoming Resources Corporation | Rapid City, SD 57702 | Oil & Gas Operator | Oct 2018 |