| 301 | J D Operating Company | Tulsa, OK 74105 | Oil & Gas Operator | Jun 2005 |
| 302 | J O C Operating Inc | Fort Worth, TX 76102-6823 | Oil & Gas Operator | Feb 2021 |
| 303 | Jac-Mac Energy Corporation | Oklahoma City, OK 73170 | Oil & Gas Operator | May 2025 |
| 304 | Jaco, Troy Inc. | Sherman, TX 75091 | Oil & Gas Operator | Jul 2025 |
| 305 | Jai Oil | Lucien, OK 73757 | Oil & Gas Operator | Apr 2025 |
| 306 | Jakmen Inc | Edmond, OK 73034-5313 | Oil & Gas Operator | Jun 2015 |
| 307 | Jan Oil Company | Oklahoma City, OK 73156 | Oil & Gas Operator | May 2006 |
| 308 | Jay Petroleum Inc | Oklahoma City, OK 73154-0526 | Oil & Gas Operator | Mar 2019 |
| 309 | Jec Operating LLC | Oklahoma City, OK 73114-2717 | Oil & Gas Operator | Apr 2025 |
| 310 | Jeffries Pumping Service Inc | Guthrie, OK 73044-8761 | Oil & Gas Operator | Apr 2025 |
| 311 | Jena Operating Company, Inc. | Dallas, TX 75367 | Oil & Gas Operator | May 2007 |
| 312 | Jet Oil Co12/Ofb See 18649 | | Oil & Gas Operator | Jul 2007 |
| 313 | Johnson Bates Drilling Co Inc | Konawa, OK 74849 | Oil & Gas Operator | Aug 2002 |
| 314 | Johnson Bill M Production Co | Perry, OK 73077-1238 | Oil & Gas Operator | Oct 2018 |
| 315 | Jones Loyd | Perryton, TX 79070-0931 | Oil Operator | Jan 2022 |
| 316 | Jones Loyd Well Serv Co Inc | Perryton, TX 79070 | Oil & Gas Operator | Dec 2005 |
| 317 | K & M Oil Company LLC | Hennessey, OK 73742 | Oil & Gas Operator | Apr 2025 |
| 318 | K S Oil Company Inc | Norman, OK 73072-7480 | Oil & Gas Operator | May 2025 |
| 319 | Kahn George Operating Co | Seminole, OK 74818 | Oil & Gas Operator | Nov 2000 |
| 320 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Jul 2025 |
| 321 | Kate F H | Oklahoma City, OK 73122 | Oil & Gas Operator | Jun 2000 |
| 322 | Kato Operating Company | Bristow, OK 74010 | Oil & Gas Operator | Mar 2015 |
| 323 | Keener Oil & Gas Company | Tulsa, OK 74119-4416 | Oil & Gas Operator | May 2025 |
| 324 | Keener Oil Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2018 |
| 325 | Kelloil Inc | Fort Worth, TX 76116-5600 | Oil & Gas Operator | Mar 2015 |
| 326 | Kelly Jr Walter A Opr Co | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2014 |
| 327 | Kenworthy Operating Company | Tulsa, OK 74132 | Oil & Gas Operator | May 2009 |
| 328 | Key Energy Corporation | Enid, OK 73702-5349 | Oil & Gas Operator | Oct 2017 |
| 329 | Kibtec Oil & Gas Inc | Cashion, OK 73016 | Oil & Gas Operator | Aug 2024 |
| 330 | Kiester Operating Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Mar 2025 |
| 331 | Kingfisher CSG Pullr & Const Inc | Hennessey, OK 73742-0024 | Oil & Gas Operator | Apr 2014 |
| 332 | Kirkpatrick Oil Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Jul 2025 |
| 333 | KJR Services LLC | Edmond, OK 73083 | Oil & Gas Operator | Feb 2025 |
| 334 | Klo LLC | Tulsa, OK 74120-2428 | Oil & Gas Operator | May 2025 |
| 335 | Kloberdanz, Paul E. | Oklahoma City, OK 73157 | Oil & Gas Operator | Aug 2021 |
| 336 | Koby Oil Company LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2025 |
| 337 | Koda Operating LLC | Tyler, TX 75703-5596 | Oil & Gas Operator | Apr 2025 |
| 338 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 339 | L E Jones Operating Inc | Duncan, OK 73534 | Oil & Gas Operator | May 2025 |
| 340 | Ladder Energy Company | Tulsa, OK 74120-4281 | Oil & Gas Operator | Jan 2018 |
| 341 | Lakeshore Operating, LLC | Wichita, KS 67203 | Oil & Gas Operator | Jul 2025 |
| 342 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | Apr 2025 |
| 343 | Lance Ruffel Oil & Gas LLC | Oklahoma City, OK 73102-5632 | Oil & Gas Operator | May 2025 |
| 344 | Las Colinas Oil Corp. | Irving, TX 75062 | Oil & Gas Operator | Mar 2015 |
| 345 | Lauck & Associates | Walnut Creek, CA 91789 | Oil & Gas Operator | Jan 2025 |
| 346 | Laurel Operating Company, Inc. | Stillwater, OK 74074-3025 | Oil & Gas Operator | Apr 2025 |
| 347 | Lawrence Roy Drilling Co Inc | Pawnee, OK 74058-0306 | Oil & Gas Operator | Aug 2000 |
| 348 | Le Bas Operating Company, Inc. | Giddings, TX 78942 | Oil & Gas Operator | Mar 2000 |
| 349 | Le Norman Energy Corporation | Duncan, OK 73534 | Oil & Gas Operator | Nov 2014 |
| 350 | Leavell Resources Corporation | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 351 | Lee Energy Exploration LTD | Oklahoma City, OK 73102-7114 | Oil & Gas Operator | Jul 2008 |
| 352 | Legacy - M & K Corporation | Dallas, TX 75231-0969 | Oil & Gas Operator | Jan 2025 |
| 353 | Legacy Energy Services LLC | Stillwater, OK 74074 | Oil & Gas Operator | Apr 2025 |
| 354 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Jul 2025 |
| 355 | Leigh Operating Co | Dallas, TX 75205 | Oil & Gas Operator | Mar 2008 |
| 356 | Lewbet Inc | Perry, OK 73077 | Oil & Gas Operator | Aug 2024 |
| 357 | Lewis Oil Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2025 |
| 358 | Lewis, R. J. Oil Company | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2014 |
| 359 | Likins-Foster Honolulu Corp | Foster City, CA 94404 | Oil & Gas Operator | Feb 2015 |
| 360 | Link Oil Company (The) | Tulsa, OK 74103-4113 | Oil & Gas Operator | Jan 2014 |
| 361 | Lion Petroleum Company | Oklahoma City, OK 73120-4503 | Oil & Gas Operator | Aug 2015 |
| 362 | Little Bear Resources LLC | Stillwater, OK 74074-1388 | Oil & Gas Operator | Feb 2013 |
| 363 | Little River Energy Company | Drumright, OK 74030 | Oil & Gas Operator | May 2025 |
| 364 | Lu-Ray Petroleum LLC | Oklahoma City, OK 73121-1607 | Oil & Gas Operator | May 2025 |
| 365 | Luween Energy LLC | Oklahoma City, OK 73128 | Oil & Gas Operator | Apr 2025 |
| 366 | LVM Oil Production LLC | Yale, OK 74085-6688 | Oil & Gas Operator | Jul 2021 |
| 367 | M E Klein & Associates LLC | Washington, OK 73093-4663 | Oil & Gas Operator | May 2025 |
| 368 | M K W Inc | Oklahoma City, OK 73112-8884 | Oil & Gas Operator | Dec 2009 |
| 369 | M M Energy, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Apr 2025 |
| 370 | M M Resources, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Sep 2018 |
| 371 | Mack Oil Company | Duncan, OK 73534 | Oil & Gas Operator | Nov 2000 |
| 372 | Mackellar Inc | Oklahoma City, OK 73116-7101 | Oil & Gas Operator | May 2025 |
| 373 | Magaw & Zimmer | Perry, OK 73077-1055 | Oil & Gas Operator | Aug 2013 |
| 374 | Maggard Oil Co Inc | Manford, OK 74044 | Oil & Gas Operator | Sep 1997 |
| 375 | Maggard Supply & Oil Company | Mannford, OK 74044-1407 | Oil & Gas Operator | Nov 2014 |
| 376 | Magnolia Petroleum Inc | Tulsa, OK 74106-2433 | Oil Operator | Jun 2018 |
| 377 | Maier Resources Inc | Oklahoma City, OK 73157-2996 | Oil & Gas Operator | Mar 2015 |
| 378 | Mallard Oil & Gas | Cody, WY 82414-9640 | Oil & Gas Operator | Oct 2019 |
| 379 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 380 | Manna Corporation | Oklahoma City, OK 73162 | Oil & Gas Operator | Dec 2014 |
| 381 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | May 2025 |
| 382 | Mar-Bar Enterprises Inc | Cushing, OK 74023-3031 | Oil Operator | Apr 2025 |
| 383 | Marbet LLC | Edmond, OK 73013-6691 | Oil & Gas Operator | Apr 2025 |
| 384 | Marcus Exploration Inc | Piedmont, OK 73078-0308 | Oil & Gas Operator | Dec 2000 |
| 385 | Marjo Oil Company | Lockhart, TX 78644 | Oil & Gas Operator | Oct 1999 |
| 386 | Marjo Operating Company Inc | Tulsa, OK 741010729 | Oil & Gas Operator | Apr 2025 |
| 387 | Marjo Operating Mid-Continent LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 388 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Apr 2025 |
| 389 | Martin'S Resources LLC | Woodward, OK 73801-5641 | Oil & Gas Operator | Apr 2025 |
| 390 | Mason Robert A Production Co | Edmond, OK 73013-9102 | Oil & Gas Operator | May 2013 |
| 391 | Mathews Exploration Corporation | Oklahoma City, OK 73155-5328 | Oil & Gas Operator | Mar 2015 |
| 392 | Matthews Florine D | Bristow, OK 74010 | Oil & Gas Operator | Jan 2020 |
| 393 | Maxim Energy Corporation | Baytown, TX 77520 | Oil & Gas Operator | Apr 2025 |
| 394 | May Petroleum, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Nov 1998 |
| 395 | McAninch J W | Tonkawa, OK 74653 | Oil & Gas Operator | Nov 2000 |
| 396 | McAninch Michael E | Tonkawa, OK 74653-4415 | Oil & Gas Operator | May 2013 |
| 397 | McAninch W Kent | Tonkawa, OK 74653-4216 | Oil & Gas Operator | Oct 2016 |
| 398 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | Jun 2025 |
| 399 | McMillin C C & Company Inc | Guthrie, OK 73044 | Oil & Gas Operator | Apr 2025 |
| 400 | McNeal Production Inc | Perry, OK 73077-0268 | Oil & Gas Operator | Nov 2014 |