| 1201 | Schiff & Jackson Oil Producers | Dallas, TX 75206 | Oil & Gas Operator | Apr 2025 |
| 1202 | Schlaikjer A L | | Oil Operator | Feb 1997 |
| 1203 | Schmid Properties Inc | Hico, TX 76457 | Oil & Gas Operator | Jul 2025 |
| 1204 | Schneider Oil Corporation | Broomfield, CO 80020 | Oil & Gas Operator | Aug 2009 |
| 1205 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 1206 | Seahawk Oil International Inc | Newport Beach, CA 92660 | Oil & Gas Operator | Oct 1997 |
| 1207 | Seedy Draw LLC | Greenwood VIllage, CO 80111 | Oil Operator | Apr 2025 |
| 1208 | Seer Operating LLC | Sheridan, WY 82801 | Oil & Gas Operator | Oct 2016 |
| 1209 | Seguro Oil & Gas Inc | | Oil Operator | Jul 1992 |
| 1210 | Sendero Resources LLC | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 1211 | Seven Sisters Oil & Gas LLC | Casper, WY 82602 | Oil & Gas Operator | Jan 2022 |
| 1212 | Sgcu GP LLC | Casper, WY 82602 | Oil Operator | May 2025 |
| 1213 | Shar Alan Oil Company | | Oil & Gas Operator | Oct 2005 |
| 1214 | Sharkey Well Service Inc | | Oil Operator | Dec 2023 |
| 1215 | Sharples Phillip T Trust | Denver, CO 80264 | Oil & Gas Operator | Nov 2020 |
| 1216 | Shelco | Maysville, MO 64469 | Oil & Gas Operator | May 2021 |
| 1217 | Shell Rocky Mountain Production LLC | Pinedale, WY 82941 | Oil & Gas Operator | Dec 2008 |
| 1218 | Shenandoah Energy Inc | Denver, CO 80265-1050 | Oil & Gas Operator | Dec 2014 |
| 1219 | Shenandoah Oil Corporation | | Oil & Gas Operator | Jun 1979 |
| 1220 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Apr 2025 |
| 1221 | Siegfried R H Inc | Tulsa, OK 74104 | Oil & Gas Operator | Mar 2008 |
| 1222 | Sierra Trading Corporation | | Oil & Gas Operator | Sep 1978 |
| 1223 | Signal Hill Company LLC | Cody, WY 82414 | Oil & Gas Operator | Dec 2024 |
| 1224 | Signal Hill Operating LLC | | Oil & Gas Operator | Jun 2025 |
| 1225 | Silverado Oil Inc | Greeley, CO 80631 | Oil Operator | Apr 2000 |
| 1226 | Simasko Production Co | Denver, CO 80204 | Oil & Gas Operator | Nov 1997 |
| 1227 | Simon Oil LLC | Kaycee, WY 82639 | Oil Operator | Apr 2025 |
| 1228 | Simray Production Company LP | Richland, TX 75080 | Oil & Gas Operator | Dec 2010 |
| 1229 | Six Bar Oil LLC | Pine Haven, WY 82721 | Oil & Gas Operator | May 2025 |
| 1230 | Skidgel Enterprises Inc | Rawlins, WY 82301 | Oil & Gas Operator | Sep 2018 |
| 1231 | Skinner Corporation | | Oil Operator | Apr 1985 |
| 1232 | Skinner Oil & Gas LLC | Gillette, WY 82717 | Oil & Gas Operator | Jan 2024 |
| 1233 | Skinner'S Resources & Expl Inc | | Oil & Gas Operator | Jun 2007 |
| 1234 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Jul 2025 |
| 1235 | Skull Creek A LLC | Douglas, WY 82633 | Oil & Gas Operator | Apr 2025 |
| 1236 | Skyline Oil Company | Salt Lake City, UT 84111 | Oil & Gas Operator | Jan 1987 |
| 1237 | Slaughter J M Oil Company | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2001 |
| 1238 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 1239 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Jul 2025 |
| 1240 | Smith Al | Duncan, OK 73534-0037 | Oil Operator | Dec 1998 |
| 1241 | Smith Conley P Operating Co | Eglewood, CO 80112-3640 | Oil & Gas Operator | Jun 2000 |
| 1242 | Smith Kevin | Thermopolis, WY 82443 | Oil Operator | Sep 2024 |
| 1243 | Smith Red Plains Production LLC | | Oil & Gas Operator | Jun 2025 |
| 1244 | Smokey Gap Oil Company LLC | | Oil Operator | May 2025 |
| 1245 | Smokey Oil Company Inc | Casper, WY 82601 | Oil & Gas Operator | Dec 1996 |
| 1246 | Snowy Owl LLC | Gillette, WY 82717 | Oil & Gas Operator | May 2025 |
| 1247 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 1248 | Sois-Osage Inc | | Oil & Gas Operator | Oct 2006 |
| 1249 | Solar Petroleum Inc | | Oil Operator | May 1983 |
| 1250 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 1251 | Sonoma Energy Corporation | Park City, UT 84068 | Oil & Gas Operator | Feb 2010 |
| 1252 | Sonterra Energy LLC | Wichita, KS 67226 | Oil & Gas Operator | Jul 2022 |
| 1253 | Sooner Operating Co Inc | Casper, WY 83602 | Oil Operator | Jun 2025 |
| 1254 | Sourcegas Energy Services Co | Golden, CO 80401 | Gas Operator | Jun 2015 |
| 1255 | South Coast Oil Corporation | Boulder, CO 80302 | Oil & Gas Operator | Oct 2015 |
| 1256 | South Pass Petroleum Inc | Casper, WY 82601 | Oil & Gas Operator | May 2025 |
| 1257 | Southern Mineral Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2001 |
| 1258 | Southern States Petroleum Corp | | Oil Operator | Jan 1984 |
| 1259 | Southern Union Exploration | | Oil Operator | Jan 1990 |
| 1260 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 1261 | Southland Royalty Company LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2021 |
| 1262 | Southport Exploration Inc | Tulsa, OK 74103-4015 | Oil & Gas Operator | Nov 1998 |
| 1263 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 1264 | Southwestern Production Corporation | Lakewood, CO 80228 | Oil & Gas Operator | Jun 2025 |
| 1265 | Spellbound Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2025 |
| 1266 | Spirit Energy Inc | Edmond, OK 73034 | Oil & Gas Operator | Apr 1999 |
| 1267 | Spring Valley Development Co LLC | Centennial, CO 80014 | Oil & Gas Operator | May 2025 |
| 1268 | St Michael Exploration | | Oil & Gas Operator | Jun 1987 |
| 1269 | St Oil Company | Denver, CO 80264-2101 | Oil & Gas Operator | Dec 2010 |
| 1270 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 1271 | Stag Oil Producers Inc | Midland, TX 79701 | Oil & Gas Operator | Jan 1998 |
| 1272 | Stanco Petroleum Inc | Kimball, NE 69145 | Oil & Gas Operator | Jul 1999 |
| 1273 | Star Oil Operating Company LLC | Laramie, WY 82073 | Oil & Gas Operator | Jun 2025 |
| 1274 | Star Resources LLC | Englewood, CO 80155-5185 | Oil & Gas Operator | Dec 2013 |
| 1275 | States Exploration Inc | | Oil Operator | Jul 1985 |
| 1276 | Statex Petroleum Inc | Dallas, TX 75229 | Oil & Gas Operator | Dec 2000 |
| 1277 | Stealth Energy Inc | Billings, MT 59101 | Oil Operator | Dec 2011 |
| 1278 | Stealth Energy USA Inc | Billings, MT 59104 | Oil Operator | Dec 2017 |
| 1279 | Steamboat Oil And Gas LLC | Gillette, WY 82717 | Oil Operator | May 2025 |
| 1280 | Stellar Oil Company | Arvada, CO 80006 | Oil & Gas Operator | Dec 1998 |
| 1281 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | May 2025 |
| 1282 | Sterling Energy Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 1995 |
| 1283 | Stewart Petroleum Corporation | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Dec 2023 |
| 1284 | Stone & Wolf LLC | Sheridan, WY 82801 | Oil & Gas Operator | Dec 2006 |
| 1285 | Stone Energy Corporation | Denver, CO 80202-2828 | Oil & Gas Operator | Oct 2014 |
| 1286 | Stone Energy LLC | Denver, CO 80202 | Oil & Gas Operator | May 2005 |
| 1287 | Stone Petroleum Corporation | | Oil & Gas Operator | Dec 1996 |
| 1288 | Storm Cat Energy USA Operating Corp | Denver, CO 80202 | Gas Operator | Jun 2017 |
| 1289 | Stovall Oil Company | Casper, WY 82602 | Oil & Gas Operator | Aug 1998 |
| 1290 | Strachan Exploration Inc | Englewood, CO 80112 | Oil & Gas Operator | Apr 2025 |
| 1291 | Stringer E M | | Oil Operator | May 1996 |
| 1292 | Stripper Oil Company Inc | | Oil Operator | Feb 2025 |
| 1293 | Stroud Petroleum, Inc. | Shreveport, LA 71162 | Oil & Gas Operator | Jul 2025 |
| 1294 | Summit Gas Resources Inc | Sheridan, WY 82801 | Gas Operator | Dec 2023 |
| 1295 | Summit Operating LLC | Boulder, CO 80301 | Oil & Gas Operator | Apr 2025 |
| 1296 | Summit Resources, Inc. | Houston, TX 77077 | Oil & Gas Operator | Sep 2016 |
| 1297 | Suncor Energy Natural Gas America Inc | Greenwood VIllage, CO 80111 | Gas Operator | Feb 2010 |
| 1298 | Sundance Energy Inc | Denver, CO 80202 | Oil & Gas Operator | Jul 2014 |
| 1299 | Sundance Oil Exploration Co | | Oil Operator | Mar 1986 |
| 1300 | Sunshine Valley Petroleum | Casper, WY 82605 | Oil & Gas Operator | May 2025 |