| 301 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Nov 2025 |
| 302 | Marmac Petroleum | | Oil & Gas Operator | Oct 1994 |
| 303 | Marmac Petroleum Company | Denver, CO 80222 | Oil Operator | Apr 1998 |
| 304 | Martin Oil Produ | | Oil & Gas Operator | Dec 1994 |
| 305 | Maverick Oil Co. | Richland, TX 76681 | Oil Operator | Dec 2025 |
| 306 | Maxwell Operating Co., Inc. | Englewood, CO 80155 | Oil Operator | Jan 2007 |
| 307 | Mays, Sam W., Jr. Estate | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2005 |
| 308 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | Nov 2025 |
| 309 | McElvain Energy Inc | Denver, CO 80265 | Oil & Gas Operator | Nov 2019 |
| 310 | Meier Joe Oil Op | | Oil Operator | Jul 1983 |
| 311 | Melrose Group In | | Oil Operator | Feb 1994 |
| 312 | Meltzer Oil Comp | | Oil Operator | Dec 1983 |
| 313 | Meridian Energy Inc. | | Oil Operator | Sep 2025 |
| 314 | Merit Energy Company, LLC | Dallas, TX 75009 | Oil & Gas Operator | Sep 2025 |
| 315 | Mesa Operating L | | Oil & Gas Operator | Dec 1996 |
| 316 | Messman Corporation | Wichita, KS 67208 | Oil & Gas Operator | Sep 2025 |
| 317 | Michael D. Weilert Oil Company | | Oil Operator | Sep 2025 |
| 318 | Mid America Ener | | Oil Operator | Nov 1993 |
| 319 | Mid Continent Resources, Inc. | Houston, TX 77060 | Oil & Gas Operator | Dec 2025 |
| 320 | Mid-Continent Energy Corp. | Wichita, KS 67208 | Oil & Gas Operator | Sep 2025 |
| 321 | Mid-Continent Re | | Oil & Gas Operator | Jan 1993 |
| 322 | Mike Kelso Oil, Inc. | Chase, KS 67524 | Oil & Gas Operator | Sep 2025 |
| 323 | Mikol Oil LLC | Hays, KS 67601 | Oil Operator | Sep 2025 |
| 324 | Miura Petroleum | | Oil Operator | Dec 1992 |
| 325 | MJT Oil | | Oil Operator | Sep 2025 |
| 326 | Mohawk Petroleum | | Oil & Gas Operator | Jan 1995 |
| 327 | Murfin Drilling | | Oil & Gas Operator | Jul 1997 |
| 328 | Murfin Drilling Company, Inc. | Wichita, KS 67202 | Oil & Gas Operator | Nov 2025 |
| 329 | Mustang Drilling | | Oil & Gas Operator | Nov 1996 |
| 330 | Mustang Energy Corporation | Hays, KS 67601 | Oil Operator | Sep 2025 |
| 331 | MW Oil, Inc | | Oil & Gas Operator | Sep 2025 |
| 332 | N-B Company Inco | | Oil & Gas Operator | Apr 1992 |
| 333 | Nadel & Gussman | Tulsa, OK 74103 | Oil & Gas Operator | May 2007 |
| 334 | Nadel And Gussman LLC | Tulsa, OK 74119 | Oil & Gas Operator | Dec 2025 |
| 335 | National Coopera | | Oil & Gas Operator | Mar 1992 |
| 336 | National Develop | | Oil & Gas Operator | Jan 1990 |
| 337 | National Oil Com | | Oil & Gas Operator | Oct 1992 |
| 338 | New Age Oil LLC | Hays, KS 67601 | Oil & Gas Operator | Sep 2025 |
| 339 | New London Oil I | | Oil Operator | Dec 1996 |
| 340 | Nixon R P Operat | | Oil Operator | Aug 1995 |
| 341 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Dec 2025 |
| 342 | Norstar Petroleum Inc | Englewood, CO 80112 | Oil & Gas Operator | Sep 2025 |
| 343 | Oil Company Of America, Inc. | Hays, KS 67601 | Oil Operator | Dec 2009 |
| 344 | Oil Internationa | | Oil Operator | Jun 1986 |
| 345 | Oil Producers In | | Oil & Gas Operator | Dec 1996 |
| 346 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | Dec 2025 |
| 347 | Okmar Oil Compan | | Oil & Gas Operator | Feb 1995 |
| 348 | Oryx Energy Comp | | Oil & Gas Operator | Apr 1991 |
| 349 | Owen'S Pumping Service | | Oil Operator | Sep 2025 |
| 350 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Dec 2025 |
| 351 | P.O.&G. Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Dec 2025 |
| 352 | Palomino Petroleum | Newton, KS 67114 | Oil Operator | Oct 2003 |
| 353 | Pan Western Energy Corporation | Tulsa, OK 74114 | Oil & Gas Operator | Dec 2025 |
| 354 | Panhandle Petrol | | Oil Operator | Jun 1987 |
| 355 | Paradise Creek Oil & Gas | Plainville, KS 67663 | Oil Operator | Jun 2025 |
| 356 | Patterson Energy LLC | Hays, KS 67601 | Oil & Gas Operator | Sep 2025 |
| 357 | Patton Oil Compa | | Oil & Gas Operator | Nov 1994 |
| 358 | Patton Oil Company | Midland, TX 79702 | Oil & Gas Operator | Jun 2007 |
| 359 | Paul Bowman Oil Trust | Codell, KS 67663 | Oil Operator | Sep 2025 |
| 360 | Peak Operating LLC | Oklahoma City, OK 73157 | Oil & Gas Operator | Sep 2025 |
| 361 | Pendleton Land & | | Oil Operator | Aug 1985 |
| 362 | Petr Corporation | | Oil Operator | Apr 1988 |
| 363 | Petro Dynamics C | | Oil & Gas Operator | Sep 1988 |
| 364 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 365 | Petroleum Energy | | Oil & Gas Operator | Mar 1991 |
| 366 | Petroleum Incorp | | Oil & Gas Operator | Apr 1993 |
| 367 | Petroleum Manage | | Oil & Gas Operator | Oct 1994 |
| 368 | Petroleum Property Services, Inc. | Wichita, KS 67202 | Oil & Gas Operator | Sep 2025 |
| 369 | Pfeifer Explorations, LLC | Hays, KS 67601 | Oil Operator | Sep 2025 |
| 370 | Phillips Petrole | | Oil & Gas Operator | May 1995 |
| 371 | Pickrell Drilling Co., Inc. | Wichita, KS 67213 | Oil & Gas Operator | Sep 2025 |
| 372 | Piland Resources | | Oil & Gas Operator | Mar 2022 |
| 373 | Pintail Petroleum, LTD. | Wichita, KS 67202 | Oil & Gas Operator | Apr 2021 |
| 374 | Pioneer Resources | Jefferson, CO 80456 | Oil Operator | Dec 2009 |
| 375 | Pioneer Resources Inc | Phillipsburg, KS 67661 | Oil & Gas Operator | Oct 2020 |
| 376 | Pratt Well Service, Inc. | Pratt, KS 67124 | Oil & Gas Operator | Sep 2025 |
| 377 | Pratt, Don E. | Hays, KS 67601 | Oil Operator | Dec 1999 |
| 378 | Price Robert R O | | Oil Operator | Apr 1995 |
| 379 | Price, Robert R. Operating, Inc. | Tulsa, OK 74147 | Oil Operator | May 1996 |
| 380 | Producers Equipm | | Oil Operator | Dec 1996 |
| 381 | Production Drill | | Oil Operator | Oct 1994 |
| 382 | Production Drilling, Inc. | Hays, KS 67601 | Oil Operator | Sep 2025 |
| 383 | Prospect Oil & G | | Oil Operator | Feb 1996 |
| 384 | Prospect Oil & Gas Corp | Russell, KS 67665 | Oil Operator | Sep 2025 |
| 385 | Pyle Petroleum, Inc. | Tyler, TX 75703 | Oil & Gas Operator | Apr 2025 |
| 386 | Quest Energy LLC | Salina, KS 67401 | Oil Operator | Sep 2025 |
| 387 | Quinn Oil Produc | | Oil Operator | Dec 1987 |
| 388 | R. J. Oil Co. | Olney, TX 76374 | Oil & Gas Operator | May 2025 |
| 389 | R. P. Nixon Operations, Inc | Hays, KS 67601 | Oil Operator | Sep 2025 |
| 390 | Rains & Williams | | Oil & Gas Operator | Nov 1995 |
| 391 | Rains & Williamson Oil Co Inc | Wichita, KS 67277 | Oil & Gas Operator | Sep 2025 |
| 392 | Rama Operating Company Inc | Stafford, KS 67578 | Oil & Gas Operator | Nov 2025 |
| 393 | Raney Oil Company, LLC | Lawrence, KS 66049 | Oil & Gas Operator | Sep 2025 |
| 394 | Range Oil Co., Inc. | Wichita, KS 67278 | Oil & Gas Operator | Jan 2020 |
| 395 | Range Oil Compan | | Oil & Gas Operator | Nov 1995 |
| 396 | Rapid Well Service, Inc. | Russell, KS 67665 | Oil Operator | Aug 2025 |
| 397 | Raymond Oil Co., Inc. | Wichita, KS 67201 | Oil & Gas Operator | Sep 2025 |
| 398 | Raymond Oil Comp | | Oil & Gas Operator | Dec 1996 |
| 399 | Reach Petroleum | | Oil & Gas Operator | Jan 1994 |
| 400 | Rebel Oil LLC | | Oil Operator | Sep 2025 |