| 4301 | Transamerica Oil | | Oil & Gas Operator | Sep 1992 |
| 4302 | Transamerica Oil Corporation | Hutchinson, KS 67504 | Gas Operator | Mar 2025 |
| 4303 | Trapp Oil Oper - | | Oil Operator | Aug 1989 |
| 4304 | Trees Oil Compan | | Oil Operator | Jan 1995 |
| 4305 | Trek Aec, LLC | Wichita, KS 67202 | Oil & Gas Operator | Dec 2025 |
| 4306 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Apr 2026 |
| 4307 | Tremo Corporation | Toronto, KS 66777 | Oil Operator | May 1998 |
| 4308 | Trepco Production Company Inc | Yukon, OK 73099 | Oil & Gas Operator | Feb 2026 |
| 4309 | Tri United, Inc | Hays, KS 67601 | Oil Operator | Dec 2025 |
| 4310 | Tri-J Tubulars, Inc. | Wichita, KS 67202 | Oil Operator | Aug 1996 |
| 4311 | Tri-L Oil Co. | | Oil Operator | Sep 2015 |
| 4312 | Trich Production, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2025 |
| 4313 | Trigg Exploratio | | Gas Operator | Feb 1992 |
| 4314 | Trimble & Maclaskey Oil LLC | Gridley, KS 66852 | Oil Operator | Dec 2025 |
| 4315 | Trimble, IVal L. | Gridley, KS 66852 | Oil Operator | Dec 2019 |
| 4316 | Trinity Bay Oil & Gas, Inc. | Lubbock, TX 79416 | Oil & Gas Operator | Apr 2026 |
| 4317 | Trinity Resources, Inc. | Houston, TX 77277 | Oil & Gas Operator | May 2020 |
| 4318 | Triple "S" Well Service, Inc. | Eureka, KS 67045 | Oil Operator | Nov 2025 |
| 4319 | Triple 'H' Oil O | | Oil Operator | Apr 1992 |
| 4320 | Triple - I, Inc. | Kansas City, MO 64114 | Gas Operator | Oct 2000 |
| 4321 | Triple B Crude, LLC | Colony, KS 66015 | Oil Operator | Nov 2025 |
| 4322 | Triple C Petroleum LLC | Colony, KS 66015 | Oil Operator | Nov 2019 |
| 4323 | Triple Crown Operating LLC | Tulsa, OK 74114 | Oil Operator | Dec 2025 |
| 4324 | Triple E Drillin | | Oil Operator | Jun 1992 |
| 4325 | Triple E Oil | Sterling, KS 67579 | Oil & Gas Operator | Mar 1999 |
| 4326 | Triple G Oilfiel | | Oil & Gas Operator | Dec 1985 |
| 4327 | Triple J L.L.C. | Coffeyville, KS 67336 | Oil Operator | Mar 1999 |
| 4328 | Triple J Prod In | | Oil Operator | Sep 1989 |
| 4329 | Triple K | | Oil Operator | Jun 2007 |
| 4330 | Triple S Construction | Blue Mound, KS 66010 | Gas Operator | Dec 2025 |
| 4331 | Triple S Well Se | | Oil Operator | Dec 1996 |
| 4332 | Triple Seven, Inc. | Oklahoma City, OK 73132 | Oil & Gas Operator | Nov 1997 |
| 4333 | Triple T Oil, LLC | Louisburg, KS 66053 | Oil Operator | Dec 2025 |
| 4334 | Triple T Pipelines, Inc. | Frontenac, KS 66763 | Oil & Gas Operator | Dec 2025 |
| 4335 | Triple T Resources, LP | Dallas, TX 75205 | Oil & Gas Operator | Dec 2025 |
| 4336 | Triple-T Pipelin | | Oil & Gas Operator | Oct 1995 |
| 4337 | Tripower Resources LLC | Ardmore, OK 73402 | Oil & Gas Operator | Apr 2026 |
| 4338 | Tripower Resources, Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2020 |
| 4339 | Tritex Resc Inco | | Oil Operator | Dec 1985 |
| 4340 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 4341 | Triunited Investors, LLC | Monte Sereno, CA 95030 | Oil Operator | May 2012 |
| 4342 | Troy Jaco, Inc. | Sherman, TX 75091 | Oil Operator | Dec 2018 |
| 4343 | Troy Resources C | | Oil Operator | Jun 1990 |
| 4344 | Troyer, Wayne A. | Galva, KS 67443 | Oil Operator | Jun 1997 |
| 4345 | True Oil Company | Casper, WY 82602 | Oil & Gas Operator | Aug 2003 |
| 4346 | Trumart Oil Comp | | Oil Operator | May 1990 |
| 4347 | Trumart Oil Company | Ellis, KS 67637 | Oil Operator | Dec 2000 |
| 4348 | Tubbs Patrick | Neodesha, KS 66757 | Oil Operator | Sep 2008 |
| 4349 | Tucker, Carl H., Jr. | Independence, KS 67301 | Oil Operator | Jul 1996 |
| 4350 | Tucker, Stephen A. | Independence, KS 67301 | Oil Operator | Feb 2009 |
| 4351 | Turnco Drilling, Inc. | Portland, OR 97208 | Oil & Gas Operator | Dec 2009 |
| 4352 | Tutcher, Dan C. | Houston, TX 77002 | Oil Operator | Dec 2004 |
| 4353 | Tuthill & Barbee | Amarillo, TX 79101 | Oil & Gas Operator | Nov 1994 |
| 4354 | Twin Eagle Petro | | Oil Operator | Aug 1990 |
| 4355 | Twin M, Inc. | Kingman, KS 67068 | Oil & Gas Operator | Dec 2025 |
| 4356 | Twin Star Petrol | | Oil & Gas Operator | Jan 1989 |
| 4357 | Twinoco | Caney, KS 67333 | Oil Operator | Nov 1996 |
| 4358 | Twisted Oak Operating LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2026 |
| 4359 | TWM Production Co., A General Partnership | Chanute, KS 66720 | Oil Operator | Nov 2025 |
| 4360 | Tyco Incorporate | | Oil & Gas Operator | Oct 1995 |
| 4361 | Tyco Oil Co. | | Oil Operator | Oct 2025 |
| 4362 | Tyluka Operations, LLC | Hays, KS 67601 | Oil Operator | Sep 2025 |
| 4363 | Tyro Oil Develop | | Oil Operator | Jul 1991 |
| 4364 | Tyrok | | Oil & Gas Operator | Nov 2010 |
| 4365 | U-N-I Exploratio | | Oil & Gas Operator | Dec 1990 |
| 4366 | U-N-I Exploration & Development, Inc. | Yates Center, KS 66783 | Oil & Gas Operator | Jan 2003 |
| 4367 | Uehlin LLC | Oberlin, KS 67749 | Oil Operator | Jul 2025 |
| 4368 | Uhls, Jimmie J. | Sedan, KS 67361 | Oil Operator | Sep 2019 |
| 4369 | Ulysses, City Of | Ulysses, KS 67880 | Gas Operator | Dec 2025 |
| 4370 | Ummel'S Tank Ser | | Oil Operator | Sep 1994 |
| 4371 | Unc Texas Incorp | | Gas Operator | May 1987 |
| 4372 | Union Pacific Re | | Oil & Gas Operator | Dec 1996 |
| 4373 | Union Pacific Resour | | Oil & Gas Operator | Apr 2002 |
| 4374 | Union Texas Petroleum | Houston, TX 77252 | Oil & Gas Operator | Oct 1991 |
| 4375 | Union Valley Petroleum Corp | Enid, OK 73701 | Oil & Gas Operator | Feb 2026 |
| 4376 | Unionville Explo | | Oil Operator | Jul 1984 |
| 4377 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2026 |
| 4378 | United Energy & Exploration LLC | Ada, OK 74821 | Oil & Gas Operator | Feb 2026 |
| 4379 | United Energy, Inc. | Wichita, KS 67230 | Oil & Gas Operator | Dec 2002 |
| 4380 | United Meridian | | Oil Operator | Dec 1992 |
| 4381 | United Oil & Gas | | Oil Operator | Feb 1988 |
| 4382 | United Petroleum | | Oil Operator | Mar 1986 |
| 4383 | United Petroleum Corporation | Edgwater, CO 80214 | Oil & Gas Operator | May 1996 |
| 4384 | United Reserve G | | Oil Operator | Aug 1987 |
| 4385 | United States Exploration, Inc. | Denver, CO 80802 | Oil & Gas Operator | Apr 2007 |
| 4386 | Universal Resour | | Oil & Gas Operator | Dec 1996 |
| 4387 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 4388 | Unknown | Houston, TX 77208 | Oil & Gas Operator | Dec 2024 |
| 4389 | Unrein Oil Co | | Oil Operator | Dec 2025 |
| 4390 | Unruh, Elmer | Galva, KS 67443 | Oil & Gas Operator | Aug 1998 |
| 4391 | Unruh, Mark D. | Peru, KS 67360 | Oil Operator | Sep 2011 |
| 4392 | Upland Resources | | Oil Operator | Jul 1983 |
| 4393 | Upland Resources LLC | Canadian, TX 79014 | Oil & Gas Operator | Apr 2026 |
| 4394 | Upland Resources, Inc. | Canadian, TX 79014 | Oil & Gas Operator | Dec 2009 |
| 4395 | Uranus, Inc. | Kansas City, MO 64112 | Oil Operator | Jan 2000 |
| 4396 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Apr 2026 |
| 4397 | Us Energy Exploration Corp | Rural Valley, PA 16249 | Oil & Gas Operator | Dec 2025 |
| 4398 | Us Oil Resources LLC | Lakewood, CO 80123 | Oil Operator | Dec 2025 |
| 4399 | Usins Oil Compan | | Oil Operator | Jan 1993 |
| 4400 | Usx Operating Co., Inc. | Barnstall, OK 74002 | Oil & Gas Operator | Apr 2017 |