| 1201 | Stealth Energy USA Inc | Billings, MT 59104 | Oil Operator | Dec 2017 |
| 1202 | Steamboat Oil And Gas LLC | Gillette, WY 82717 | Oil Operator | Dec 2025 |
| 1203 | Stellar Oil Company | Arvada, CO 80006 | Oil & Gas Operator | Dec 1998 |
| 1204 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Dec 2025 |
| 1205 | Sterling Energy Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 1995 |
| 1206 | Stewart Petroleum Corporation | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Dec 2023 |
| 1207 | Stone & Wolf LLC | Sheridan, WY 82801 | Oil & Gas Operator | Dec 2006 |
| 1208 | Stone Energy Corporation | Denver, CO 80202-2828 | Oil & Gas Operator | Oct 2014 |
| 1209 | Stone Energy LLC | Denver, CO 80202 | Oil & Gas Operator | May 2005 |
| 1210 | Stone Petroleum Corporation | | Oil & Gas Operator | Dec 1996 |
| 1211 | Storm Cat Energy USA Operating Corp | Denver, CO 80202 | Gas Operator | Jun 2017 |
| 1212 | Stovall Oil Company | Casper, WY 82602 | Oil & Gas Operator | Aug 1998 |
| 1213 | Strachan Exploration Inc | Englewood, CO 80112 | Oil & Gas Operator | Nov 2025 |
| 1214 | Stringer E M | | Oil Operator | May 1996 |
| 1215 | Stripper Oil Company Inc | | Oil Operator | Sep 2025 |
| 1216 | Stroud Petroleum, Inc. | Shreveport, LA 71162 | Oil & Gas Operator | Feb 2026 |
| 1217 | Summit Gas Resources Inc | Sheridan, WY 82801 | Gas Operator | Dec 2023 |
| 1218 | Summit Operating LLC | Boulder, CO 80301 | Oil & Gas Operator | Nov 2025 |
| 1219 | Summit Resources, Inc. | Houston, TX 77077 | Oil & Gas Operator | Sep 2016 |
| 1220 | Suncor Energy Natural Gas America Inc | Greenwood VIllage, CO 80111 | Gas Operator | Feb 2010 |
| 1221 | Sundance Energy Inc | Denver, CO 80202 | Oil & Gas Operator | Jul 2014 |
| 1222 | Sundance Oil Exploration Co | | Oil Operator | Mar 1986 |
| 1223 | Sunshine Valley Petroleum | Casper, WY 82605 | Oil & Gas Operator | Dec 2025 |
| 1224 | Supron Energy Corp | | Oil & Gas Operator | Oct 1995 |
| 1225 | Surtek Inc | | Oil & Gas Operator | May 1993 |
| 1226 | Survivor Oil Inc | Tulsa, OK 74133 | Oil & Gas Operator | Sep 2007 |
| 1227 | Swenco-Western Inc | Houston, TX 77060 | Oil & Gas Operator | Jan 1997 |
| 1228 | Swepi LP | Houston, TX 77079 | Oil & Gas Operator | Jul 2020 |
| 1229 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 1230 | Synergy Offshore LLC | Houston, TX 77024 | Oil & Gas Operator | Feb 2022 |
| 1231 | Synergy Operating LLC | Farmington, NM 87499 | Oil & Gas Operator | Nov 2025 |
| 1232 | T P Production Co | Denver, CO 80202 | Oil & Gas Operator | Nov 1996 |
| 1233 | T-Rex Oil Inc | Broomfield, CO 80021 | Oil Operator | Feb 2011 |
| 1234 | T2 Operating Corporation | Denver, CO 80202 | Oil & Gas Operator | Feb 2026 |
| 1235 | Tap Management Inc | Austin, TX 78757 | Oil & Gas Operator | Jan 2023 |
| 1236 | Taqa USA, Inc. | Centennial, CO 80111 | Oil & Gas Operator | Jul 2020 |
| 1237 | Tara Oil Company | | Oil Operator | Dec 1981 |
| 1238 | Target Oil Company | | Oil & Gas Operator | Mar 2007 |
| 1239 | Taylor Oil #13 LLC | Lander, WY 82520 | Oil Operator | Dec 2025 |
| 1240 | Tbi Exploration Inc | Englewood, CO 801556525 | Oil & Gas Operator | Jun 2011 |
| 1241 | TCF Inc | | Gas Operator | Dec 1993 |
| 1242 | Team Operating, L.L.C. | Pinehurst, TX 77362 | Oil & Gas Operator | Feb 2026 |
| 1243 | Teapot Oil & Refining Company | Billings, MT 59101 | Oil & Gas Operator | Mar 2012 |
| 1244 | Temagami Oil & Gas LTD | | Oil & Gas Operator | May 2007 |
| 1245 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Nov 2025 |
| 1246 | Teocali Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 1247 | Terex Energy Corporation | Casper, WY 82602 | Oil & Gas Operator | Aug 2019 |
| 1248 | Terrapet Corporation | | Oil & Gas Operator | Jun 2011 |
| 1249 | Territory Resources LLC | Stillwater, OK 74074-1869 | Oil & Gas Operator | Jan 2026 |
| 1250 | Terry Production Co | Stroud, OK 74079-0475 | Oil & Gas Operator | Aug 2008 |
| 1251 | Tesoro Petroleum Corporation | | Oil & Gas Operator | May 1982 |
| 1252 | Tex/Con Oil & Gas Company | Houston, TX 77074 | Oil & Gas Operator | Feb 2001 |
| 1253 | Texaco Exploration & Prod | Midland, TX 79702 | Oil & Gas Operator | Aug 2002 |
| 1254 | Texakota | | Oil & Gas Operator | Mar 1995 |
| 1255 | Texas American Oil Corporation | Midland, TX 79701 | Oil & Gas Operator | Jan 2001 |
| 1256 | Texas American Resources Company | Austin, TX 78701 | Oil & Gas Operator | Feb 2026 |
| 1257 | Texas Gas Exploration Corp. | | Oil & Gas Operator | Nov 1986 |
| 1258 | Texas General Petroleum Corp | | Oil & Gas Operator | Aug 1984 |
| 1259 | Texas Oil & Gas Corporation | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 1260 | Texas Vanguard Oil Company | Austin, TX 78720 | Oil & Gas Operator | Jan 2014 |
| 1261 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 1262 | Thayer Donald D | Labarge, WY 83123 | Oil & Gas Operator | Jan 2015 |
| 1263 | The Brinkerhoff Company | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 1264 | The Termo Company | Long Beach, CA 90801 | Oil & Gas Operator | Dec 2025 |
| 1265 | Thomas Operating Company Inc | Greeley, CO 80634 | Oil & Gas Operator | Aug 2008 |
| 1266 | Three Forks Resources, LLC | Wheat Ridge, CO 80033 | Oil & Gas Operator | Feb 2026 |
| 1267 | Three G Inc | Cody, WY 82414 | Oil & Gas Operator | Dec 1999 |
| 1268 | Three Sisters LLC | Cheyenne, WY 82001 | Oil Operator | Nov 2025 |
| 1269 | Thunder Basin Resources LLC | Denver, CO 80203 | Oil & Gas Operator | Jul 2023 |
| 1270 | Ticony Inc | | Oil & Gas Operator | Dec 1989 |
| 1271 | Tidemark Exploration | Tulsa, OK 74170 | Oil & Gas Operator | May 2005 |
| 1272 | Tiger Oil Company | Dallas, TX 75221 | Oil & Gas Operator | May 2007 |
| 1273 | Timberline Energy Inc | Franklin, PA 16323-0269 | Oil & Gas Operator | Dec 2025 |
| 1274 | Timberline Production Company LLC | Casper, WY 82601 | Oil & Gas Operator | Oct 2020 |
| 1275 | Tindall Operating Company | Englewood, CO 80112 | Oil & Gas Operator | Jan 2025 |
| 1276 | Tipperary Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 1277 | Tipps Kenneth L | | Oil & Gas Operator | Jun 2000 |
| 1278 | Titan Exploration LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 1279 | Toc Oil Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 1280 | Toc-Rocky Mountain Inc | | Oil & Gas Operator | Oct 2013 |
| 1281 | Toco Corporation | | Oil & Gas Operator | Oct 1991 |
| 1282 | Tonka Oil & Gas Production Inc | Buffalo, WY 82834 | Oil & Gas Operator | Sep 1999 |
| 1283 | Torch E & P Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2015 |
| 1284 | Torch Oil & Gas Company | Houston, TX 77010 | Oil & Gas Operator | Aug 1997 |
| 1285 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 1286 | Total Petroleum Inc | Houston, TX 77210 | Oil & Gas Operator | Feb 1998 |
| 1287 | Townsend Company | Abilene, TX 79608 | Oil & Gas Operator | Dec 2021 |
| 1288 | TR Operating LLC | Graham, TX 76450 | Oil Operator | Dec 2025 |
| 1289 | Transco Exploration Company | | Oil & Gas Operator | Jul 1989 |
| 1290 | Transcontinental Oil Corp. | | Oil & Gas Operator | Sep 1985 |
| 1291 | Transglobe Oil & Gas Corporation | Littleton, CO 801222710 | Oil & Gas Operator | Dec 1999 |
| 1292 | Transhorizon Energy Inc | Cheyenne, WY 82003 | Oil & Gas Operator | Jul 2023 |
| 1293 | Transworld Systems Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Sep 2025 |
| 1294 | Trend Exploration I LLC | Midland, TX 79701 | Oil & Gas Operator | May 2011 |
| 1295 | Tresor Petroleum | | Oil & Gas Operator | Sep 1987 |
| 1296 | Tressler John R & IVa M | | Oil Operator | Apr 1989 |
| 1297 | Tri-Ex Corporation | | Oil & Gas Operator | Jan 1985 |
| 1298 | Triangle J Oil Company | | Oil & Gas Operator | Mar 2007 |
| 1299 | Tribar Resources LLC | | Oil & Gas Operator | Dec 2025 |
| 1300 | Trigg Drilling Company Inc | Oklahoma City, OK 73105 | Oil & Gas Operator | Jan 2013 |