| 301 | KRS Oil Company | Frisco, TX 75034 | Oil & Gas Operator | Apr 2020 |
| 302 | KT Energy Inc | Enid, OK 73702-2365 | Oil & Gas Operator | May 2026 |
| 303 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | May 2026 |
| 304 | Ladd Petroleum Corp. | Denver, CO 80202 | Oil & Gas Operator | Oct 2004 |
| 305 | Ladder Energy Company | Tulsa, OK 74120-4281 | Oil & Gas Operator | Jan 2018 |
| 306 | Lakeshore Operating, LLC | Wichita, KS 67203 | Oil & Gas Operator | Sep 2026 |
| 307 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | May 2026 |
| 308 | Lance Ruffel Oil & Gas LLC | Oklahoma City, OK 73102-5632 | Oil & Gas Operator | Jun 2026 |
| 309 | Lancer Energy Corporation | Oklahoma City, OK 73132-5903 | Oil & Gas Operator | May 2015 |
| 310 | Landers & Musgrove | Okemah, OK 74859 | Oil & Gas Operator | Mar 2015 |
| 311 | Landers & Musgrove Oil Co. Inc | Okemah, OK 74859-0266 | Oil & Gas Operator | Jan 2018 |
| 312 | Larkspur Operating LLC | Oklahoma City, OK 73106 | Oil & Gas Operator | May 2026 |
| 313 | Latex Petroleum Corp. | Houston, TX 77090 | Oil & Gas Operator | Aug 2012 |
| 314 | Laurco Energies,Inc | | Oil & Gas Operator | May 2025 |
| 315 | LCB Resources LLC | Kingfisher, OK 73750-2322 | Oil & Gas Operator | Jun 2026 |
| 316 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Sep 2026 |
| 317 | Leigh Operating Co | Dallas, TX 75205 | Oil & Gas Operator | Mar 2008 |
| 318 | Lewis A. Hembree Production Company | Shawnee, OK 74801 | Oil & Gas Operator | May 2026 |
| 319 | Likins-Foster Honolulu Corp | Foster City, CA 94404 | Oil & Gas Operator | Feb 2015 |
| 320 | Lime Rock Resources A, L.P. | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 321 | Lime Rock Resources II-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 322 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Jun 2025 |
| 323 | Little River Energy Company | Drumright, OK 74030 | Oil & Gas Operator | Jun 2026 |
| 324 | Lobar Oil Co LLC | Edmond, OK 73013 | Oil & Gas Operator | May 2026 |
| 325 | Longbranch Oil Company | Oklahoma City, OK 73154-0735 | Oil & Gas Operator | Mar 2018 |
| 326 | Loto Energy LLC | Saint Louis, MO 63105 | Oil & Gas Operator | Jun 2026 |
| 327 | Loy G Boyle Dba High Energy | Ripley, OK 74062 | Oil & Gas Operator | Apr 2026 |
| 328 | Lu-Ray Petroleum LLC | Oklahoma City, OK 73121-1607 | Oil & Gas Operator | Jun 2026 |
| 329 | M M Energy Inc | Oklahoma City, OK 73156 | Oil & Gas Operator | May 2026 |
| 330 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | Sep 2026 |
| 331 | Mackellar Inc | Oklahoma City, OK 73116-7101 | Oil & Gas Operator | Jun 2026 |
| 332 | Magaw & Zimmer | Perry, OK 73077-1055 | Oil & Gas Operator | Aug 2013 |
| 333 | Magnatex Corp | Midland, TX 79702-1311 | Oil & Gas Operator | Feb 1995 |
| 334 | Magnum Energy Inc | Norman, OK 73072-2403 | Oil & Gas Operator | Jun 2026 |
| 335 | Majors, Linda K | | Oil Operator | Apr 2026 |
| 336 | Mallorn Energy LLC | Edmond, OK 73034 | Oil & Gas Operator | May 2026 |
| 337 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Jun 2026 |
| 338 | Mapco Production Co | Billings, MT 59102 | Oil & Gas Operator | Apr 1994 |
| 339 | Marathon Oil Company LLC | Houston, TX 77079 | Oil & Gas Operator | Jun 2026 |
| 340 | Marjo Oil Company | Lockhart, TX 78644 | Oil & Gas Operator | Oct 1999 |
| 341 | Marjo Operating Co., Inc. | Tulsa, OK 741010729 | Oil & Gas Operator | Apr 2026 |
| 342 | Marjo Operating Mid-Continent LLC | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2026 |
| 343 | Mark Holloway Inc | Oklahoma City, OK 73107-6526 | Oil & Gas Operator | May 2026 |
| 344 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | May 2026 |
| 345 | Martin Jr, James U | | Oil & Gas Operator | May 2026 |
| 346 | Mason Robert A | | Oil Operator | May 1993 |
| 347 | Maverick Brothers Resources LLC | Enid, OK 73701 | Oil & Gas Operator | May 2026 |
| 348 | Mayo Ross L Inc | Oklahoma City, OK 73120-1426 | Oil & Gas Operator | Jan 1997 |
| 349 | McCord Al Inc | Norman, OK 73072-6720 | Oil & Gas Operator | Feb 2011 |
| 350 | MCM Energy Inc | Edmond, OK 73013-8035 | Oil & Gas Operator | Nov 2021 |
| 351 | McMillin C C & Company Inc | Guthrie, OK 73044 | Oil & Gas Operator | May 2026 |
| 352 | Meade Energy Corporation | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | Jun 2026 |
| 353 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Jun 2026 |
| 354 | Mermac Operating Company Inc | Norman, OK 73072 | Oil & Gas Operator | Mar 2015 |
| 355 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 356 | Metropolitan Resources Corp | Tulsa, OK 74169-1734 | Oil & Gas Operator | Mar 2015 |
| 357 | Mid-Con Central Expl Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2014 |
| 358 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Jul 2026 |
| 359 | Midwest Energy Corporation | Tulsa, OK 74105-6083 | Oil & Gas Operator | Aug 2016 |
| 360 | Midwest Operating Company Inc | Tulsa, OK 74105-6059 | Oil & Gas Operator | Nov 1999 |
| 361 | Midwest Pipe & Supply Company | Oklahoma City, OK 73154-0245 | Oil & Gas Operator | Dec 2008 |
| 362 | Mija LLC | Oklahoma City, OK 73151 | Oil & Gas Operator | Jun 2026 |
| 363 | Miracle Production Inc | Yukon, OK 73085-0680 | Oil & Gas Operator | Jun 2007 |
| 364 | Mito Resources LLC | Edmond, OK 73013 | Oil & Gas Operator | May 2026 |
| 365 | MJM Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Aug 2003 |
| 366 | Monroe Natural Gas Inc | Norman, OK 73071 | Oil & Gas Operator | May 2026 |
| 367 | Moore & Moore Energy Inc | Purcell, OK 73080-0674 | Oil & Gas Operator | Dec 2012 |
| 368 | Moore Clay | Bradenton, FL 34211 | Oil & Gas Operator | May 2026 |
| 369 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Sep 2026 |
| 370 | Mullen William Company | Edmond, OK 73083-1372 | Oil & Gas Operator | May 1999 |
| 371 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 372 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Sep 2026 |
| 373 | Mutual Oil & Gas Co | Akron, OH 44311 | Oil & Gas Operator | Dec 2000 |
| 374 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 375 | National Cooperative RFG Assoc | McPherson, KS 67460-1404 | Oil & Gas Operator | Oct 2025 |
| 376 | National Energy Group Inc | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 377 | Neg Operating LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | May 2026 |
| 378 | New Century Petroleum Corp | Oklahoma City, OK 73105 | Oil & Gas Operator | May 2013 |
| 379 | New Dominion LLC | Tulsa, OK 74119-3220 | Oil & Gas Operator | Jun 2026 |
| 380 | Nexco Inc | Oklahoma City, OK 73102-6801 | Oil & Gas Operator | Nov 2013 |
| 381 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Sep 2026 |
| 382 | Noble Energy Production Inc | Houston, TX 77067 | Oil & Gas Operator | Sep 2026 |
| 383 | Nomoc Oil Company Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | May 2006 |
| 384 | North Star Exploration Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Mar 2026 |
| 385 | Northport Production Company | Oklahoma City, OK 73113 | Oil & Gas Operator | May 2026 |
| 386 | Nossaman E Oil Inc | Del City, OK 73155-5449 | Oil Operator | Oct 2002 |
| 387 | Oasis Energy Resources LLC | Norman, OK 73072-9668 | Oil & Gas Operator | Jun 2025 |
| 388 | Oexco, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 389 | Oklahoma Energy Acquisitions LP | Houston, TX 77094-1900 | Oil & Gas Operator | May 2026 |
| 390 | Oklahoma Equipment & Salvage | Oklahoma City, OK 73120-5903 | Oil & Gas Operator | Mar 2015 |
| 391 | Oklahoma Oil & Gas MGMT Inc | Edmond, OK 73083-6786 | Oil & Gas Operator | Apr 2026 |
| 392 | Oklahoma Oil Tactics Inc | Edmond, OK 73003-1351 | Oil & Gas Operator | Mar 2015 |
| 393 | Oklahoma Tank Service Inc | Oklahoma City, OK 73143 | Oil Operator | Aug 1997 |
| 394 | Okland Oil Company | Oklahoma City, OK 73102-9022 | Oil & Gas Operator | Jun 2026 |
| 395 | Omni Oil & Gas, Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2017 |
| 396 | Oneok Gas Transportation Co | Tulsa, OK 74121-2089 | Oil & Gas Operator | Oct 2014 |
| 397 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 398 | Onshore Royalties LLC | Houston, TX 77269 | Oil & Gas Operator | Jun 2026 |
| 399 | Onyx Energy Corporation | Oklahoma City, OK 73157 | Oil & Gas Operator | May 1994 |
| 400 | Optima Exploration LLC | Tulsa, OK 74116-5664 | Oil & Gas Operator | Mar 2015 |