| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Walker L Willis | Oil Operator | Dec 1985 | |
| 2 | Washakie Oil Company | Oil & Gas Operator | Dec 1989 | |
| 3 | Washington Energy Exploration | Oil & Gas Operator | Dec 1997 | |
| 4 | Waterford Production Co | Oil Operator | Oct 1992 | |
| 5 | Wellstar Corporation | Northglenn, CO 80233 | Oil & Gas Operator | Sep 2024 |
| 6 | Wesco Operating, Inc. | Casper, WY 82602 | Oil & Gas Operator | Sep 2024 |
| 7 | Western American Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2024 |
| 8 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 9 | Wichita River Oil Corporation | Englewood, CO 80111 | Oil & Gas Operator | Apr 2009 |
| 10 | Winter Ridge Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Sep 2011 |
| 11 | Wold Oil Properties Inc | Denver, CO 80203 | Oil & Gas Operator | Feb 2018 |
| 12 | Wyoming Resources Corporation | Rapid City, SD 57702 | Oil & Gas Operator | Oct 2018 |