| 301 | Simmons Mack McCoy | Cement, OK 73017 | Oil Operator | Nov 2024 |
| 302 | Simmons, L.B. Energy, Inc. | Midland, TX 79705 | Oil & Gas Operator | Nov 2000 |
| 303 | Simon Joseph W | Carney, OK 74832-0443 | Oil & Gas Operator | Dec 2016 |
| 304 | Simon Oil Company | Ardmore, OK 73401-1045 | Oil Operator | Sep 2024 |
| 305 | Simon Royce & Joyce | Tecumseh, OK 74873-7341 | Oil Operator | Jun 2018 |
| 306 | Simpson Oil & Land Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2025 |
| 307 | Sinclair Oil & Gas Company | Salt Lake Cty, UT 84130 | Oil & Gas Operator | Mar 2025 |
| 308 | Singer Fleischaker Oil Op. Co. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2002 |
| 309 | Singer Joseph B Expl Co | Oklahoma City, OK 73118-7486 | Oil & Gas Operator | Mar 1993 |
| 310 | Singer Oil Co LLC | Hennessey, OK 73742 | Oil & Gas Operator | Jan 2025 |
| 311 | Singer Oil Company | Oklahoma City, OK 73148 | Oil & Gas Operator | Dec 2024 |
| 312 | Siosi Oil & Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Nov 2013 |
| 313 | Sitco Inc | Yukon, OK 73099 | Oil & Gas Operator | Jul 1995 |
| 314 | Siven Crude Oil Company | Lomita, CA 90717 | Oil & Gas Operator | Apr 2018 |
| 315 | Six "E" Trading Company | Henryetta, OK 74801 | Oil & Gas Operator | Sep 2020 |
| 316 | SJ Ok Oil Company | Dallas, TX 75206-9925 | Oil & Gas Operator | Dec 2024 |
| 317 | SJM Inc | Tulsa, OK 74133-1757 | Gas Operator | Apr 2006 |
| 318 | Sju Holdings LLC | Norman, OK 73072 | Oil & Gas Operator | Dec 2024 |
| 319 | SK Nemaha LLC | Houston, TX 77079-1222 | Oil & Gas Operator | Feb 2021 |
| 320 | SK Plymouth LLC | Houston, TX 77079-1222 | Oil & Gas Operator | Dec 2024 |
| 321 | Skeet Oil Production LLC | Grady, OK 73569 | Oil Operator | Jan 2025 |
| 322 | Skelly Oil Co | | Oil & Gas Operator | Mar 2005 |
| 323 | Skip'S Oilfield Service | Pawhuska, OK 74056 | Oil & Gas Operator | Jan 2006 |
| 324 | Skull Creel Oil & Gas LLC | Bartlesville, OK 74005 | Oil Operator | Nov 2024 |
| 325 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Jan 2025 |
| 326 | SL Petroleum LLC | Edmond, OK 73013-8801 | Oil & Gas Operator | Apr 2022 |
| 327 | Slavens II Paul R | Tulsa, OK 74131-2244 | Oil & Gas Operator | Dec 2024 |
| 328 | Slawson Clifford Ray | Healdton, OK 73438 | Oil Operator | Jan 1995 |
| 329 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2025 |
| 330 | Slawson, Donald C. | Wichita, KS 67202 | Oil & Gas Operator | Oct 2024 |
| 331 | Sledge Olen | Duncan, OK 73533 | Oil Operator | Nov 2024 |
| 332 | Slick Production Inc | Tulsa, OK 74132-1718 | Oil & Gas Operator | Apr 2020 |
| 333 | Slim Hole Inc | Farmington, NM 87401-7725 | Oil & Gas Operator | May 2013 |
| 334 | Slinkard William & Roberta | Pawhuska, OK 74056 | Oil Operator | Sep 2024 |
| 335 | Sloan Oil Corporation | Humble, TX 77347 | Oil & Gas Operator | Mar 2015 |
| 336 | Sloan Petroleum Service Inc | Guthrie, OK 73044 | Oil & Gas Operator | Jan 2025 |
| 337 | Sloan Production Co | | Oil Operator | Jan 2013 |
| 338 | Slone VIctor | Barnsdall, OK 74002 | Oil Operator | Apr 2024 |
| 339 | SLS Operating LLC | Seminole, OK 74868-5876 | Oil & Gas Operator | Dec 2024 |
| 340 | SLT Dakota Operating, Inc. | Yukon, OK 73099 | Oil & Gas Operator | Mar 2025 |
| 341 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Mar 2025 |
| 342 | SM Oil & Gas Inc | Skiatook, OK 74070 | Oil & Gas Operator | Dec 2024 |
| 343 | Smart H D Etal | | Oil Operator | Jan 2006 |
| 344 | Smart Jr T J | Ryan, OK 73565 | Oil Operator | Sep 1994 |
| 345 | Smart Service & Equipment LLC | Muskogee, OK 74401-5262 | Oil Operator | Aug 2013 |
| 346 | Smiley Drilling Co | Oklahoma City, OK 73156-0773 | Oil & Gas Operator | Apr 1999 |
| 347 | Smith & Smith Petroleum Corp | | Oil & Gas Operator | Aug 2024 |
| 348 | Smith Al | Duncan, OK 73534-0037 | Oil Operator | Dec 1998 |
| 349 | Smith Alfred Dba A-S Oil | Walters, OK 73572 | Oil Operator | Dec 2024 |
| 350 | Smith B R Jr Disposal Co | Erick, OK 73645 | Oil & Gas Operator | Jun 2021 |
| 351 | Smith Bart Oil & Gas Expl Inc | Council Hill, OK 74428-9603 | Oil & Gas Operator | Apr 2015 |
| 352 | Smith Bob W | Ardmore, OK 73403-5214 | Oil & Gas Operator | Sep 2014 |
| 353 | Smith Bradley D & Paul C | Pawhuska, OK 74056 | Oil Operator | Dec 2024 |
| 354 | Smith Brothers Enterprises | Ardmore, OK 73402 | Oil Operator | Jul 1998 |
| 355 | Smith C W & Associates Inc | Oklahoma City, OK 73178-0105 | Oil & Gas Operator | Aug 2013 |
| 356 | Smith Cheryl A | Copan, OK 74022-4914 | Oil Operator | Jul 2024 |
| 357 | Smith Claude W | Henryetta, OK 74437-7553 | Oil Operator | May 2008 |
| 358 | Smith Conley P Operating Co | Eglewood, CO 80112-3640 | Oil & Gas Operator | Jun 2000 |
| 359 | Smith Connie M & Sheryle | Chelsea, OK 74016-1959 | Oil Operator | Feb 2017 |
| 360 | Smith Doug | Tulsa, OK 74107 | Oil & Gas Operator | Feb 2016 |
| 361 | Smith Edward F | Avant, OK 74001-0024 | Oil & Gas Operator | Nov 2014 |
| 362 | Smith Energy Company LLC | Purcell, OK 73080-4772 | Oil & Gas Operator | May 2015 |
| 363 | Smith Harmon K | Wewoka, OK 74884 | Oil & Gas Operator | Jan 2013 |
| 364 | Smith J S Production | Seminole, OK 74868 | Oil & Gas Operator | Dec 2024 |
| 365 | Smith Jack Boyd | Elkhart, IN 46515-1968 | Oil & Gas Operator | Oct 2011 |
| 366 | Smith Joyce | Okmulgee, OK 74447-6074 | Oil Operator | Nov 2024 |
| 367 | Smith Manus L MFG Inc | Oklahoma City, OK 73147 | Oil & Gas Operator | Nov 1998 |
| 368 | Smith Max Dean | Wewoka, OK 74884 | Oil & Gas Operator | Dec 2024 |
| 369 | Smith Mike D | Stillwater, OK 74074 | Oil & Gas Operator | Apr 2015 |
| 370 | Smith Oil & Gas Co., Inc. | Wichita Falls, TX 76310 | Oil Operator | Dec 2010 |
| 371 | Smith Patrica\Judith Miller | Collinsville, OK 74021-6307 | Oil Operator | Jun 2010 |
| 372 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Mar 2025 |
| 373 | Smith Petroleum LLC | Barnsdall, OK 74002-0134 | Oil Operator | Dec 2024 |
| 374 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Mar 2025 |
| 375 | Smith Resources, L.L.C. | Marshall, TX 75671 | Oil & Gas Operator | Mar 2025 |
| 376 | Smith Richard L | Catoosa, OK 74015 | Oil & Gas Operator | Dec 2019 |
| 377 | Smith Shirley C | Claremore, OK 74017-0060 | Oil & Gas Operator | Mar 2015 |
| 378 | Smith Terry | Wewoka, OK 74884 | Oil & Gas Operator | Mar 2015 |
| 379 | Smith Vernon C | Tulsa, OK 74104-4611 | Oil & Gas Operator | Oct 2024 |
| 380 | Smith VIcki L Palmer | Lawton, OK 73505-1701 | Oil & Gas Operator | Dec 2014 |
| 381 | Smith W M | Barnstall, OK 74002 | Oil & Gas Operator | Dec 2024 |
| 382 | Smith, W.T. | Panhandle, TX 79068 | Oil & Gas Operator | Nov 2005 |
| 383 | Smith-Clement Exploration Inc | Edmond, OK 73013 | Oil Operator | Jul 1997 |
| 384 | Smither Energy Co LLC | Broken Arrow, OK 74011-7615 | Oil & Gas Operator | Nov 2020 |
| 385 | Smiths Investment Inc | Sperry, OK 74073-4198 | Oil Operator | Dec 2024 |
| 386 | Smokey Trail LLC | Thornton, CO 80241 | Oil & Gas Operator | Jan 2025 |
| 387 | Snake Creek Oil & Gas Inc | Okmulgee, OK 74447-2041 | Oil & Gas Operator | Dec 2024 |
| 388 | Sneed Drilling Company | Cleveland, OK 74020 | Oil & Gas Operator | Jul 2024 |
| 389 | Sneed William A Bill | Cleveland, OK 74020-1007 | Oil & Gas Operator | Dec 2024 |
| 390 | Snelgrooes Oil Company Inc | Maysville, OK 73057-0631 | Oil & Gas Operator | Nov 2014 |
| 391 | Snelgrooes Well Service Inc | Elmore City, OK 73433 | Oil & Gas Operator | May 2003 |
| 392 | SNR Central Oklahoma Operating LLC | Oklahoma City, OK 73116-7906 | Oil Operator | Jan 2025 |
| 393 | SNR Operating, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2025 |
| 394 | Snuffy'S Oilfield Service Inc | Hennessey, OK 73742-6511 | Oil & Gas Operator | Nov 2014 |
| 395 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 396 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 397 | Snyder Partners | Cody, WY 82414 | Oil & Gas Operator | Jan 2025 |
| 398 | Sogc, Inc. | Salt Lake Cty, UT 84131 | Oil & Gas Operator | Jan 2025 |
| 399 | Sonata Oil & Gas Corp Inc | Stratford, OK 74812 | Oil & Gas Operator | Apr 2014 |
| 400 | Song Production Company | Lindsay, OK 73052-0369 | Oil & Gas Operator | Jun 2015 |