| 101 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 102 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 103 | Staghorn Energy, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Aug 2024 |
| 104 | Stone Energy Corporation | Denver, CO 80202-2828 | Oil & Gas Operator | Oct 2014 |
| 105 | Stone Energy LLC | Denver, CO 80202 | Oil & Gas Operator | May 2005 |
| 106 | Summit Resources, Inc. | Houston, TX 77077 | Oil & Gas Operator | Sep 2016 |
| 107 | Taqa USA, Inc. | Centennial, CO 80111 | Oil & Gas Operator | Jul 2020 |
| 108 | Texaco Expl. And Prod. Inc. | Houston, TX 77236 | Oil & Gas Operator | Jul 2024 |
| 109 | Three Forks Resources LLC | Wheat Ridge, CO 80033 | Oil & Gas Operator | Dec 2024 |
| 110 | Tipperary Oil & Gas Corp | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 111 | Triangle USA Petroleum Corporation | Denver, CO 80202 | Oil & Gas Operator | Jul 2021 |
| 112 | True Oil LLC | Casper, WY 82602 | Oil & Gas Operator | Oct 2024 |
| 113 | U Bee Tea Production LLC | Culbertson, MT 59218 | Oil & Gas Operator | Sep 2024 |
| 114 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2024 |
| 115 | Upton Resources U.S.A. Inc. | | Oil & Gas Operator | Oct 2013 |
| 116 | Vaalco Energy (USA), Inc. | Houston, TX 77042 | Oil & Gas Operator | Dec 2016 |
| 117 | Vess Oil Corporation | Dallas, TX 75201 | Oil & Gas Operator | Dec 2024 |
| 118 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Aug 2024 |
| 119 | Ward Petroleum Corporation | Enid, OK 73702 | Oil & Gas Operator | Sep 2024 |
| 120 | Western Meadowlark Resources LLC | Denver, CO 80206 | Oil & Gas Operator | Aug 2024 |
| 121 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 122 | Wheless Industries, Inc. | Shreveport, LA 71101-5301 | Oil & Gas Operator | Sep 2002 |
| 123 | White Rock Oil & Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | Dec 2024 |
| 124 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 125 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jul 2024 |
| 126 | Williston Industrial Supply Corporation | Williston, ND 58801 | Oil & Gas Operator | Mar 2012 |
| 127 | Wyoming Resources Corporation | Rapid City, SD 57702 | Oil & Gas Operator | Oct 2018 |
| 128 | Xoil Inc | Aurora, CO 80016 | Oil & Gas Operator | Jul 2023 |