| 301 | Klima Well Servi | | Oil Operator | Dec 1996 |
| 302 | Klima Well Service, Inc. | Great Bend, KS 67530 | Oil & Gas Operator | Jun 2025 |
| 303 | Knighton Oil Com | | Oil & Gas Operator | Nov 1996 |
| 304 | Kodiak Petroleum, Inc. | Englewood, CO 80155 | Oil & Gas Operator | Jun 2025 |
| 305 | Koehn Eldon R | | Oil Operator | Dec 2009 |
| 306 | Koron Investments, Inc. | Hays, KS 67601 | Oil Operator | Jun 2025 |
| 307 | Kraft, Jim - Oil Operations | Holyrood, KS 67450 | Oil Operator | Jan 1999 |
| 308 | Kratzer Oil LLC | | Oil Operator | Jun 2025 |
| 309 | Krier Kirby Oil | | Oil Operator | Dec 1996 |
| 310 | Krier Oil Oper - | | Oil Operator | Sep 1995 |
| 311 | Krier Oil Operation | | Oil Operator | May 2025 |
| 312 | Krier, Kirby Oil, Inc. | Claflin, KS 67525 | Oil Operator | Jun 2025 |
| 313 | Kruckenberg & SC | | Oil & Gas Operator | Sep 1993 |
| 314 | Kruckenberg & Scott | Isabel, KS 67065 | Oil Operator | Dec 2011 |
| 315 | Krug, Donald H | Russell, KS 67665 | Oil Operator | Jun 2025 |
| 316 | Kytex, Inc. | Wichita, KS 67230 | Oil Operator | Dec 2019 |
| 317 | L & B Oil | Longton, KS 67352 | Oil Operator | Dec 2019 |
| 318 | L & R Oil, Inc. | Great Bend, KS 67530 | Oil Operator | Jun 2025 |
| 319 | L B Exploration Inc | Wichita, KS 67205 | Oil & Gas Operator | Jul 2025 |
| 320 | L-K Wireline, Inc. | Hays, KS 67601 | Oil Operator | Dec 2019 |
| 321 | L. D. Drilling, Inc. | Great Bend, KS 67530 | Oil & Gas Operator | Jun 2025 |
| 322 | Lackey, Donna | Waxahachie, TX 75165 | Oil Operator | Oct 2019 |
| 323 | Ladd Petroleum C | | Oil & Gas Operator | Sep 1989 |
| 324 | Langston Oil & Gas LLC | Wichita, KS 67202 | Oil Operator | May 2025 |
| 325 | Lansing Energy Operations | Wichita, KS 67202 | Oil Operator | Apr 2010 |
| 326 | Lario Oil & Gas | | Oil & Gas Operator | Nov 1995 |
| 327 | Larson Operating Company | Olmitz, KS 67564-8561 | Oil & Gas Operator | Dec 2019 |
| 328 | Lasmo Energy Cor | | Oil Operator | Feb 1990 |
| 329 | Lasso Energy LLC | Chase, KS 67524 | Oil & Gas Operator | Jun 2025 |
| 330 | Lauck D R Oil Co | | Oil & Gas Operator | Oct 1995 |
| 331 | Lebsack Oil Production Inc. | Stafford, KS 67578 | Oil & Gas Operator | Jun 2025 |
| 332 | Leo Michaelis Oil Operator | | Oil Operator | Oct 2002 |
| 333 | Leroy Holt Oil Operations | | Oil Operator | Mar 2010 |
| 334 | Loewen Operator, Inc. | Canton, KS 67428 | Oil & Gas Operator | Jun 2025 |
| 335 | Lucky Iron | | Oil Operator | Jun 2025 |
| 336 | M G Oil Inc | Russell, KS 67665 | Oil Operator | Jun 2025 |
| 337 | Mad Dog Oil Co. | | Oil Operator | Mar 2016 |
| 338 | Mad Operators LLC | | Oil & Gas Operator | Jun 2025 |
| 339 | Mai Oil Operations, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Jun 2025 |
| 340 | Manning, Gregory | Ellinwood, KS 67526 | Oil Operator | Jun 2025 |
| 341 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Jul 2025 |
| 342 | Mar-Lou Oil Co., LLC | Wilson, KS 67490 | Oil Operator | Jun 2025 |
| 343 | Marker Oil Compa | | Oil Operator | Jul 1985 |
| 344 | Martin J S Oil O | | Oil & Gas Operator | Apr 1991 |
| 345 | McGinness Energy Company Inc | Wichita, KS 67206 | Oil & Gas Operator | Jun 2025 |
| 346 | McNeish Oil Operations | | Oil Operator | Nov 2019 |
| 347 | Meltzer Oil Comp | | Oil Operator | Dec 1983 |
| 348 | Mem Partnership LP, A General Partnership | Spring, TX 77393 | Oil Operator | Jun 2025 |
| 349 | Messman-Rinehart | | Oil & Gas Operator | Mar 1991 |
| 350 | Michaelis Leo Oi | | Oil Operator | Aug 1991 |
| 351 | Mid Continent Resources, Inc. | Houston, TX 77060 | Oil & Gas Operator | Oct 2025 |
| 352 | Midway Drilling | | Oil & Gas Operator | Dec 1996 |
| 353 | Midway Operating Co. | Great Bend, KS 67530 | Oil Operator | Jan 1998 |
| 354 | Migwis | Great Bend, KS 67530 | Oil Operator | Mar 1988 |
| 355 | Mike Kelso Oil, Inc. | Chase, KS 67524 | Oil & Gas Operator | Jun 2025 |
| 356 | Molitor Oil, Inc. | Wichita, KS 67205 | Oil & Gas Operator | Jun 2025 |
| 357 | Morgenstern Oil Operations LLC | Ellinwood, KS 67526 | Oil Operator | Jun 2025 |
| 358 | Moss Petroleum Company | Dallas, TX 75207 | Oil & Gas Operator | Oct 2025 |
| 359 | Mull Drilling Company | Wichita, KS 67206 | Oil & Gas Operator | Aug 2025 |
| 360 | Murfin Drilling | | Oil & Gas Operator | Jul 1997 |
| 361 | Murfin Drilling Company Inc | Wichita, KS 67202 | Oil & Gas Operator | Aug 2025 |
| 362 | Musgrove Petrole | | Oil & Gas Operator | Dec 1996 |
| 363 | Mustang Drilling | | Oil & Gas Operator | Nov 1996 |
| 364 | Mustang Energy Corporation | Hays, KS 67601 | Oil Operator | Jun 2025 |
| 365 | Mustang Oil & Gas Corporation | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2021 |
| 366 | MW Oil, Inc | | Oil & Gas Operator | Jun 2025 |
| 367 | Nadel And Gussman | Tulsa, OK 74103 | Oil & Gas Operator | May 2007 |
| 368 | Nadel And Gussman, L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2025 |
| 369 | National Coopera | | Oil & Gas Operator | Mar 1992 |
| 370 | National Cooperative Refinery Assoc. | Great Bend, KS 67530 | Oil & Gas Operator | Feb 2023 |
| 371 | National Oil Com | | Oil & Gas Operator | Oct 1992 |
| 372 | National Petrole | | Oil & Gas Operator | Dec 1996 |
| 373 | Ney Oil Operations | | Oil Operator | Apr 1998 |
| 374 | Nixon R P Operat | | Oil Operator | Aug 1995 |
| 375 | Norstar Petroleum Inc | Englewood, CO 80112 | Oil & Gas Operator | Jun 2025 |
| 376 | North American D | | Oil & Gas Operator | Sep 1986 |
| 377 | Northern Lights Oil Company, LLC | Andover, KS 67002 | Oil & Gas Operator | Jun 2025 |
| 378 | Northstar Investments, Inc. | Wichita, KS 67230 | Oil & Gas Operator | Jun 2025 |
| 379 | Novy Oil & Gas, Inc. | Goddard, KS 67052 | Oil & Gas Operator | Aug 2025 |
| 380 | NPF Energy Corporation | Boise, ID 83708 | Oil & Gas Operator | Jun 2025 |
| 381 | Nuss Oil Operations | | Oil & Gas Operator | Aug 1998 |
| 382 | Nuss, Kenneth J. | Russell, KS 67665 | Oil Operator | Aug 1997 |
| 383 | O'Hare Energy Co | | Oil Operator | Dec 1983 |
| 384 | Oil Internationa | | Oil Operator | Jun 1986 |
| 385 | Oil Producers In | | Oil & Gas Operator | Dec 1996 |
| 386 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | Oct 2025 |
| 387 | Oil Property Man | | Oil & Gas Operator | Jun 1995 |
| 388 | Oil-Tech Prod Co | | Oil & Gas Operator | Oct 1992 |
| 389 | Okmar Oil Compan | | Oil & Gas Operator | Feb 1995 |
| 390 | Osborn Heirs Company LTD | San Antonio, TX 78217 | Oil & Gas Operator | Jun 2025 |
| 391 | Osborn Oil & Gas | | Oil & Gas Operator | Jun 1991 |
| 392 | Owen'S Pumping Service | | Oil Operator | Jun 2025 |
| 393 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 394 | Palomino Petrole | | Oil & Gas Operator | Dec 1995 |
| 395 | Palomino Petroleum Inc | Newton, KS 67114 | Oil & Gas Operator | Jun 2025 |
| 396 | Parrish Corporation | Wichita, KS 67202 | Oil & Gas Operator | Jan 2025 |
| 397 | Partners In Crude, Inc. | Ponca City, OK 74602 | Oil & Gas Operator | Dec 1997 |
| 398 | Patterson Energy LLC | Hays, KS 67601 | Oil Operator | Jun 2025 |
| 399 | Pauley Oil | | Oil Operator | Jun 2025 |
| 400 | Peak Operating LLC | Oklahoma City, OK 73157 | Oil & Gas Operator | Jun 2025 |