| 1 | Wacker Oil Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 2 | Waggoner-Baldridge Energy | | Oil Operator | Jun 1988 |
| 3 | Wainoco Oil & Gas Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2005 |
| 4 | Wallway M J | Casper, WY 82601 | Oil & Gas Operator | Jan 1993 |
| 5 | Warren E & P Inc | Dallas, TX 75240 | Oil & Gas Operator | Dec 2024 |
| 6 | Warren Enterprises Inc | Gillette, WY 82718 | Oil Operator | Dec 2022 |
| 7 | Wasatch Energy Inc | Salt Lake City, UT 84108 | Gas Operator | Jul 1992 |
| 8 | Washakie Energies Company | Worland, WY 82401 | Oil & Gas Operator | Dec 2019 |
| 9 | Washington Energy Exploration | | Oil & Gas Operator | Dec 1997 |
| 10 | Wave Petroleum Operating LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2025 |
| 11 | Weaver Oil Inc | | Oil & Gas Operator | Oct 2011 |
| 12 | Wellstar Corporation | Northglenn, CO 80233 | Oil & Gas Operator | Feb 2025 |
| 13 | Wem Joint Venture | Gillette, WY 82716 | Oil & Gas Operator | Sep 2015 |
| 14 | Wesco Operating, Inc. | Casper, WY 82602 | Oil & Gas Operator | Feb 2025 |
| 15 | Wessely Energy Corporation | | Oil & Gas Operator | Feb 1989 |
| 16 | West Gas Inc | | Oil & Gas Operator | Dec 2017 |
| 17 | Westburne Petroleum Inc | | Oil Operator | Jun 1990 |
| 18 | Westech Energy Corporation | Denver, CO 80237 | Oil & Gas Operator | Mar 2011 |
| 19 | Western American Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2024 |
| 20 | Western Gas Resources Inc | Denver, CO 80202-1955 | Oil & Gas Operator | Dec 2007 |
| 21 | Western Interior Energy Inc. | Denver, CO 80202 | Oil & Gas Operator | Jul 2020 |
| 22 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 23 | Wexpro Company | Rock Springs, WY 82902-0458 | Oil & Gas Operator | Feb 2025 |
| 24 | Wheless Drilling Company | | Oil & Gas Operator | Dec 1989 |
| 25 | White Rock Oil & Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | Apr 2025 |
| 26 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 27 | Wichita River Oil Corporation | Englewood, CO 80111 | Oil & Gas Operator | Apr 2009 |
| 28 | Wildfire Partners Inc | Ardmore, OK 73402 | Oil & Gas Operator | Dec 2009 |
| 29 | Williams Exploration Company | | Oil & Gas Operator | Dec 1986 |
| 30 | Williams Ted H | | Oil & Gas Operator | Dec 2008 |
| 31 | Winco Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 1997 |
| 32 | Windsor Energy Group LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Aug 2021 |
| 33 | Winter Ridge Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Sep 2011 |
| 34 | WLP Oil Inc | Gillette, WY 82717 | Oil & Gas Operator | Dec 2018 |
| 35 | Wold Energy Partners LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2022 |
| 36 | Wold Oil & Gas | | Oil & Gas Operator | Oct 1996 |
| 37 | Wold Oil Properties Inc | Denver, CO 80203 | Oil & Gas Operator | Feb 2018 |
| 38 | Wolf Energy Company | | Oil & Gas Operator | Dec 1985 |
| 39 | Wolverine Operations LLC | Buffalo, WY 82834 | Gas Operator | Oct 2008 |
| 40 | Wood River Oil & Refining Co | | Oil & Gas Operator | Dec 1998 |
| 41 | Woods Petroleum Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 42 | WPX Energy Rocky Mountain LLC | Tulsa, OK 74101 | Oil & Gas Operator | Jan 2025 |
| 43 | WRC Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Feb 2025 |
| 44 | Wulf Oil Co | | Oil & Gas Operator | Dec 1984 |
| 45 | Wyatt Petroleum Corporation | Evergreen, CO 80437 | Gas Operator | Jul 2002 |
| 46 | Wyoil Corp | Buffalo, WY 82834 | Oil Operator | Jan 2025 |
| 47 | Wyoming Resources Corporation | Rapid City, SD 57702 | Oil & Gas Operator | Oct 2018 |