| 301 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Jan 2025 |
| 302 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Apr 2025 |
| 303 | Key Energy Services Inc | Midland, TX 79705-5540 | Oil Operator | Jan 2008 |
| 304 | Kibtec Oil & Gas Inc | Cashion, OK 73016 | Oil & Gas Operator | Aug 2024 |
| 305 | Kirkpatrick Oil Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Apr 2025 |
| 306 | Klo LLC | Tulsa, OK 74120-2428 | Oil & Gas Operator | Feb 2025 |
| 307 | Koch Oil Company | | Oil & Gas Operator | May 2017 |
| 308 | Kolibri Energy Us, Inc. | Thousand Oaks, CA 91320-1272 | Oil & Gas Operator | Feb 2025 |
| 309 | KRS Oil Company | Frisco, TX 75034 | Oil & Gas Operator | Apr 2020 |
| 310 | KT Energy Inc | Enid, OK 73702-2365 | Oil & Gas Operator | Jan 2025 |
| 311 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2025 |
| 312 | Ladd Petroleum Corp. | Denver, CO 80202 | Oil & Gas Operator | Oct 2004 |
| 313 | Ladder Energy Company | Tulsa, OK 74120-4281 | Oil & Gas Operator | Jan 2018 |
| 314 | Lakeshore Operating, LLC | Wichita, KS 67203 | Oil & Gas Operator | Apr 2025 |
| 315 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | Jan 2025 |
| 316 | Lance Ruffel Oil & Gas LLC | Oklahoma City, OK 73102-5632 | Oil & Gas Operator | Feb 2025 |
| 317 | Lancer Energy Corporation | Oklahoma City, OK 73132-5903 | Oil & Gas Operator | May 2015 |
| 318 | Landers & Musgrove | Okemah, OK 74859 | Oil & Gas Operator | Mar 2015 |
| 319 | Landers & Musgrove Oil Co. Inc | Okemah, OK 74859-0266 | Oil & Gas Operator | Jan 2018 |
| 320 | Larkspur Operating LLC | Oklahoma City, OK 73034 | Oil & Gas Operator | Jan 2025 |
| 321 | Latex Petroleum Corp. | Houston, TX 77090 | Oil & Gas Operator | Aug 2012 |
| 322 | Lavrco Energie Inc | Duncan, OK 73533 | Oil & Gas Operator | Oct 2024 |
| 323 | LCB Resources LLC | Kingfisher, OK 73750-2322 | Oil & Gas Operator | Feb 2025 |
| 324 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Apr 2025 |
| 325 | Leigh Operating Co | Dallas, TX 75205 | Oil & Gas Operator | Mar 2008 |
| 326 | Lewis A Hembree Production Co | Shawnee, OK 74801 | Oil & Gas Operator | Jan 2025 |
| 327 | Likins-Foster Honolulu Corp | Foster City, CA 94404 | Oil & Gas Operator | Feb 2015 |
| 328 | Lime Rock Resources A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2025 |
| 329 | Lime Rock Resources II-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2025 |
| 330 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Aug 2024 |
| 331 | Little River Energy Company | Drumright, OK 74030 | Oil & Gas Operator | Feb 2025 |
| 332 | Lobar Oil Co LLC | Oklahoma City, OK 73116-1516 | Oil & Gas Operator | Jan 2025 |
| 333 | Longbranch Oil Company | Oklahoma City, OK 73154-0735 | Oil & Gas Operator | Mar 2018 |
| 334 | Loto Energy LLC | Saint Louis, MO 63105 | Oil & Gas Operator | Jan 2025 |
| 335 | Louis Dreyfus Gas Marketing | Oklahoma City, OK 73134 | Oil & Gas Operator | Mar 2018 |
| 336 | Lu-Ray Petroleum LLC | Oklahoma City, OK 73121-1607 | Oil & Gas Operator | Feb 2025 |
| 337 | M M Energy, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Jan 2025 |
| 338 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | Apr 2025 |
| 339 | Mackellar Inc | Oklahoma City, OK 73116-7101 | Oil & Gas Operator | Feb 2025 |
| 340 | Magaw & Zimmer | Perry, OK 73077-1055 | Oil & Gas Operator | Aug 2013 |
| 341 | Magnatex Corp | Midland, TX 79702-1311 | Oil & Gas Operator | Feb 1995 |
| 342 | Magnum Energy Inc | Norman, OK 73072-2403 | Oil & Gas Operator | Feb 2025 |
| 343 | Mallorn Energy LLC | Edmond, OK 73034 | Oil & Gas Operator | Jan 2025 |
| 344 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Feb 2025 |
| 345 | Mapco Production Co | Billings, MT 59102 | Oil & Gas Operator | Apr 1994 |
| 346 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Feb 2025 |
| 347 | Marjo Oil Company | Lockhart, TX 78644 | Oil & Gas Operator | Oct 1999 |
| 348 | Marjo Operating Company Inc | Tulsa, OK 741010729 | Oil & Gas Operator | Jan 2025 |
| 349 | Marjo Operating Mid-Continent LLC | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2025 |
| 350 | Mark Holloway Inc | Oklahoma City, OK 73107-6526 | Oil & Gas Operator | Jan 2025 |
| 351 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Jan 2025 |
| 352 | Martin Jim & Julie | Wynona, OK 74084 | Oil & Gas Operator | Jan 2025 |
| 353 | Mason Robert A | | Oil Operator | May 1993 |
| 354 | Maverick Brothers Resources LLC | Enid, OK 73701 | Oil & Gas Operator | Jan 2025 |
| 355 | Mayo Ross L Inc | Oklahoma City, OK 73120-1426 | Oil & Gas Operator | Jan 1997 |
| 356 | McCord Al Inc | Norman, OK 73072-6720 | Oil & Gas Operator | Feb 2011 |
| 357 | MCM Energy Inc | Edmond, OK 73013-8035 | Oil & Gas Operator | Nov 2021 |
| 358 | McMillin C C & Company Inc | Guthrie, OK 73044 | Oil & Gas Operator | Jan 2025 |
| 359 | Meade Energy Corporation | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | Feb 2025 |
| 360 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Feb 2025 |
| 361 | Mermac Operating Company Inc | Norman, OK 73072 | Oil & Gas Operator | Mar 2015 |
| 362 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 363 | Metropolitan Resources Corp | Tulsa, OK 74169-1734 | Oil & Gas Operator | Mar 2015 |
| 364 | Mid-Con Central Expl Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2014 |
| 365 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2025 |
| 366 | Midwest Energy Corporation | Tulsa, OK 74105-6083 | Oil & Gas Operator | Aug 2016 |
| 367 | Midwest Operating Company Inc | Tulsa, OK 74105-6059 | Oil & Gas Operator | Nov 1999 |
| 368 | Midwest Pipe & Supply Company | Oklahoma City, OK 73154-0245 | Oil & Gas Operator | Dec 2008 |
| 369 | Mija LLC | Edmond, OK 73034 | Oil & Gas Operator | Feb 2025 |
| 370 | Miracle Production Inc | Yukon, OK 73085-0680 | Oil & Gas Operator | Jun 2007 |
| 371 | Mito Resources LLC | Edmond, OK 73013 | Oil & Gas Operator | Feb 2025 |
| 372 | MJM Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Aug 2003 |
| 373 | Mohawk Drilling Company | | Oil & Gas Operator | Nov 1998 |
| 374 | Monroe Natural Gas Inc | Norman, OK 73071 | Oil & Gas Operator | Jan 2025 |
| 375 | Moore & Moore Energy Inc | Purcell, OK 73080-0674 | Oil & Gas Operator | Dec 2012 |
| 376 | Moore Clay | Bradenton, FL 34211 | Oil & Gas Operator | Jan 2025 |
| 377 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Apr 2025 |
| 378 | Mullen William Company | Edmond, OK 73083-1372 | Oil & Gas Operator | May 1999 |
| 379 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 380 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Feb 2025 |
| 381 | Mutual Oil & Gas Co | Akron, OH 44311 | Oil & Gas Operator | Dec 2001 |
| 382 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 383 | National Cooperative RFG Assoc | McPherson, KS 67460-1404 | Oil & Gas Operator | Jun 2006 |
| 384 | National Energy Group, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 385 | Neg Operating LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | Nov 2024 |
| 386 | New Century Petroleum Corp | Oklahoma City, OK 73105 | Oil & Gas Operator | May 2013 |
| 387 | New Dominion LLC | Tulsa, OK 74119-3220 | Oil & Gas Operator | Jan 2025 |
| 388 | Nexco Inc | Oklahoma City, OK 73102-6801 | Oil & Gas Operator | Nov 2013 |
| 389 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Apr 2025 |
| 390 | Noble Energy Production Inc | Houston, TX 77067 | Oil & Gas Operator | Apr 2025 |
| 391 | Nomoc Oil Company Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | May 2006 |
| 392 | North Star Exploration Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Dec 2024 |
| 393 | Northport Production Company | Oklahoma City, OK 73113 | Oil & Gas Operator | Feb 2025 |
| 394 | Nossaman E Oil Inc | Del City, OK 73155-5449 | Oil Operator | Oct 2002 |
| 395 | Oasis Energy Resources LLC | Norman, OK 73072-9668 | Oil & Gas Operator | Jan 2025 |
| 396 | Oexco, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 397 | Oklahoma & Northwestern Co. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 1997 |
| 398 | Oklahoma Energy Acquisitions LP | Houston, TX 77094-1900 | Oil & Gas Operator | Jan 2025 |
| 399 | Oklahoma Equipment & Salvage | Oklahoma City, OK 73120-5903 | Oil & Gas Operator | Mar 2015 |
| 400 | Oklahoma Oil & Gas MGMT Inc | Edmond, OK 73083-6786 | Oil & Gas Operator | Jan 2025 |