| 1201 | Triple B Energy Inc | Gillette, WY 82716 | Oil Operator | Dec 1999 |
| 1202 | Tripower Resources LLC | Ardmore, OK 73402 | Oil & Gas Operator | Jul 2026 |
| 1203 | Tripp Oil Company Inc | Houston, TX 77023 | Oil & Gas Operator | Jan 1992 |
| 1204 | Tristar Energy Corporation | Casper, WY 82602 | Oil & Gas Operator | Dec 2007 |
| 1205 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 1206 | Trout Kye Jr | | Oil & Gas Operator | Dec 2010 |
| 1207 | True Oil LLC | Casper, WY 82602 | Oil & Gas Operator | May 2026 |
| 1208 | Turner Smith & Associates | Englewood, CO 80111 | Oil & Gas Operator | May 1994 |
| 1209 | Twin Arrow Inc | Rangely, CO 81648 | Oil & Gas Operator | Sep 2009 |
| 1210 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 1211 | Tyl Oil | Canon City, CO 81212 | Gas Operator | May 1994 |
| 1212 | Tyler Rockies Exploration LTD | Tyler, TX 75710-0119 | Oil & Gas Operator | Dec 2025 |
| 1213 | Tyrex Oil Company | Casper, WY 82602 | Oil & Gas Operator | May 1997 |
| 1214 | U V Industries | | Oil & Gas Operator | Jan 1993 |
| 1215 | Ultramar Oil & Gas LTD | Houston, TX 77060 | Oil & Gas Operator | Jul 1995 |
| 1216 | Underwood Oil & Gas | Casper, WY 82602 | Oil & Gas Operator | Jun 2026 |
| 1217 | Unicorn Drilling Inc | Cody, WY 82414 | Oil Operator | Dec 1998 |
| 1218 | Unioil | Denver, CO 80203 | Oil & Gas Operator | Dec 2010 |
| 1219 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 1220 | Union Texas Petroleum | Houston, TX 77252 | Oil & Gas Operator | Oct 1991 |
| 1221 | Unit Drilling & Exploration Co | Tulsa, OK 74132-5300 | Oil & Gas Operator | Mar 2026 |
| 1222 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2026 |
| 1223 | United Energy Corporation | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2026 |
| 1224 | United Natural Gas LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2020 |
| 1225 | United Natural Resources Corp | | Oil Operator | Jan 1986 |
| 1226 | United Petroleum Corporation | Edgwater, CO 80214 | Oil & Gas Operator | May 1996 |
| 1227 | United Utilities Corporation | Conroe, TX 77301 | Oil & Gas Operator | Oct 1998 |
| 1228 | Universal Fuels Company | | Oil & Gas Operator | Oct 1993 |
| 1229 | Updike Resources Inc | Newcastle, WY 82701 | Oil & Gas Operator | Jun 1998 |
| 1230 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Jul 2026 |
| 1231 | Urroz Oil & Gas LLC | Evanston, WY 82931 | Oil & Gas Operator | Jun 2020 |
| 1232 | Us Energy Corp. | Houston, TX 77057 | Oil & Gas Operator | Dec 2021 |
| 1233 | Us Ore Corporation | Pacific Beach, CA 92109 | Oil Operator | Feb 2014 |
| 1234 | USA Energy LLC | Lance Creek, WY 82222 | Oil & Gas Operator | Nov 2024 |
| 1235 | USA Exploration & Production LLC | Mills, WY 82644 | Oil & Gas Operator | Sep 2012 |
| 1236 | V A Resources LLC | Casper, WY 82601 | Oil Operator | Apr 2016 |
| 1237 | Valero Producing Company | | Oil Operator | Sep 1987 |
| 1238 | Valkyrie Operating LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2026 |
| 1239 | Van Norman Pipe And Supply | | Oil & Gas Operator | Mar 2010 |
| 1240 | Vanmark Jack | Torrington, WY 82240 | Oil Operator | Dec 1997 |
| 1241 | Vaquero Big Horn LLC | Bakersfield, CA 93309 | Oil & Gas Operator | Nov 2025 |
| 1242 | Vaquero Energy Inc | Bakersfield, CA 93309 | Oil & Gas Operator | May 2023 |
| 1243 | Vast Oil Inc | Fullerton, CA 92832 | Oil & Gas Operator | Mar 2024 |
| 1244 | Vastar Resources Inc | Houston, TX 77253 | Oil & Gas Operator | Mar 2026 |
| 1245 | VCP Wyoming LLC | | Oil Operator | May 2026 |
| 1246 | Vecta Oil & Gas LTD | Dallas, TX 75235 | Oil & Gas Operator | Mar 2026 |
| 1247 | Vector Minerals Corporation | Aurora, CO 80015 | Oil & Gas Operator | Apr 2026 |
| 1248 | Vermilion Energy USA LLC | | Oil & Gas Operator | Jul 2025 |
| 1249 | Vessels Oil & Gas Company | Denver, CO 80265 | Oil & Gas Operator | Dec 1998 |
| 1250 | Viable Resources Inc | Casper, WY 82601 | Oil & Gas Operator | Sep 1989 |
| 1251 | Vicorp Energy Inc | Denver, CO 80202-4927 | Oil & Gas Operator | Mar 2001 |
| 1252 | Viking Resources Corp | Deerfield, OH 44411-0160 | Oil & Gas Operator | Dec 2007 |
| 1253 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Apr 2026 |
| 1254 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Jul 2026 |
| 1255 | Vortex Petroleum Inc | Centennial, CO 80111 | Oil Operator | Jan 2026 |
| 1256 | Voyager Exploration Inc | Denver, CO 80202 | Oil & Gas Operator | May 2006 |
| 1257 | Wacker Oil Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 1258 | Waggoner-Baldridge Energy | | Oil Operator | Jun 1988 |
| 1259 | Wagner & Brown Limited Partnership | Midland, TX 79701 | Oil & Gas Operator | Feb 2013 |
| 1260 | Wainoco Oil & Gas Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2005 |
| 1261 | Walker L Willis | | Oil Operator | Dec 1985 |
| 1262 | Wallway M J | Casper, WY 82601 | Oil & Gas Operator | Jan 1993 |
| 1263 | Wapiti Oil & Gas LLC | Houston, TX 77024 | Oil Operator | Dec 2011 |
| 1264 | Wapiti Operating, LLC | Houston, TX 77043 | Oil & Gas Operator | Jul 2026 |
| 1265 | Ward Petroleum Corporation | Enid, OK 73702 | Oil & Gas Operator | Apr 2026 |
| 1266 | Ware House Industries | Casper, WY 82605 | Oil & Gas Operator | Dec 2013 |
| 1267 | Warrego Oil & Gas LLC | Lander, WY 82520 | Oil Operator | May 2018 |
| 1268 | Warren E & P Inc | Dallas, TX 75240 | Oil & Gas Operator | May 2026 |
| 1269 | Warren Enterprises Inc | Gillette, WY 82718 | Oil Operator | Dec 2022 |
| 1270 | Washakie Energies Company | Worland, WY 82401 | Oil & Gas Operator | Dec 2019 |
| 1271 | Washakie Oil Company | | Oil & Gas Operator | Dec 1989 |
| 1272 | Washburn Lee | Newcastle, WY 82701 | Oil Operator | Jan 2025 |
| 1273 | Washington Energy Exploration | | Oil & Gas Operator | Dec 1997 |
| 1274 | Waterford Production Co | | Oil Operator | Oct 1992 |
| 1275 | Wave Petroleum Operating LLC | Denver, CO 80202 | Oil & Gas Operator | May 2026 |
| 1276 | Weaver Dale Inc | Powell, WY 82435 | Oil Operator | Apr 2005 |
| 1277 | Weaver Oil Inc | | Oil & Gas Operator | Oct 2011 |
| 1278 | Webb Resources Inc | | Oil & Gas Operator | Dec 1985 |
| 1279 | Webster Joe | | Oil Operator | Apr 1987 |
| 1280 | Wellstar Corporation | Northglenn, CO 80233 | Oil & Gas Operator | May 2026 |
| 1281 | Wem Joint Venture | Gillette, WY 82716 | Oil & Gas Operator | Sep 2015 |
| 1282 | Wesco Operating Inc | Casper, WY 82602 | Oil & Gas Operator | May 2026 |
| 1283 | Wesco Production LLC | | Oil & Gas Operator | Jun 2025 |
| 1284 | Wessely Energy Corporation | | Oil & Gas Operator | Feb 1989 |
| 1285 | West Gas Inc | | Oil & Gas Operator | Dec 2017 |
| 1286 | Westburne Petroleum Inc | | Oil Operator | Jun 1990 |
| 1287 | Westech Energy Corporation | Denver, CO 80237 | Oil & Gas Operator | Mar 2011 |
| 1288 | Western American Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2024 |
| 1289 | Western Gas Resources Inc | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 1290 | Western Interior Energy Inc. | Denver, CO 80202 | Oil & Gas Operator | Dec 2016 |
| 1291 | Western Interior Oil & Gas Corp | Casper, WY 82602 | Oil & Gas Operator | May 2015 |
| 1292 | Western Oil Refining Company | Kemmerrer, WY 83101 | Oil & Gas Operator | Dec 1994 |
| 1293 | Western Operating Company | Denver, CO 80204 | Oil & Gas Operator | Apr 2026 |
| 1294 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 1295 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | May 2026 |
| 1296 | Wexpro Company | Rock Springs, WY 82902-0458 | Oil & Gas Operator | May 2026 |
| 1297 | Wexpro Development Company | Salt Lake City, UT 84111 | Oil & Gas Operator | May 2026 |
| 1298 | Wexpro II Company | Salt Lake City, UT 84111 | Oil & Gas Operator | May 2026 |
| 1299 | Wheless Drilling Company | | Oil & Gas Operator | Dec 1989 |
| 1300 | Whisler Enterprise Company | Erie, CO 80516 | Oil & Gas Operator | Jun 2026 |