| 301 | Heartland Exploration Inc | Edmond, OK 73013 | Oil & Gas Operator | Dec 2015 |
| 302 | Heartlands Development Co Inc | Bristow, OK 74010-3826 | Oil & Gas Operator | May 2017 |
| 303 | Hegco Canada Inc | | Oil & Gas Operator | Nov 2003 |
| 304 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jan 2024 |
| 305 | Heritage Petroleum, Inc. | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2024 |
| 306 | Hewitt Energy Group, Inc. | Salt Lake City, UT 84111 | Oil & Gas Operator | Apr 2015 |
| 307 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Apr 2024 |
| 308 | High Sierra Crude Oil& Marketing LLC | Ardmore, OK 73401 | Oil Operator | Nov 2013 |
| 309 | Highmount Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2014 |
| 310 | Hill John H | Dallas, TX 75240-7077 | Oil & Gas Operator | Jul 2015 |
| 311 | Hill Oil Company Inc | | Oil & Gas Operator | Jan 2024 |
| 312 | Hill Resources Inc | | Oil & Gas Operator | Nov 2022 |
| 313 | Hinkle Engineering, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Nov 2016 |
| 314 | Hoke Jr J T | Edmond, OK 73034 | Oil Operator | Nov 1998 |
| 315 | Hondo Oil & Gas Company | Roswell, NM 88202 | Oil & Gas Operator | Aug 2006 |
| 316 | Howco Oil And Gas | Stroud, OK 74079-9604 | Oil & Gas Operator | Mar 2015 |
| 317 | Hoyt Oil & Gas LLC | Cushing, OK 74023-0442 | Oil & Gas Operator | Jan 2024 |
| 318 | Hugoton Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2019 |
| 319 | Hulen Operating Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2024 |
| 320 | Hux Oil Company LLC | Kingfisher, OK 73750-0474 | Oil & Gas Operator | Jan 2024 |
| 321 | Hy-Carb Energy Inc | | Oil & Gas Operator | Feb 2009 |
| 322 | Ike Energy LLC | | Oil & Gas Operator | Jan 2024 |
| 323 | Inca Oil Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2009 |
| 324 | Indian Wells Oil Co | Oklahoma City, OK 73116 | Oil & Gas Operator | Jan 2000 |
| 325 | International Energy Company LLC | | Oil & Gas Operator | Jan 2024 |
| 326 | Investors Resources Corp | Enid, OK 73702-1852 | Oil & Gas Operator | Feb 2024 |
| 327 | J D Operating Company | Tulsa, OK 74105 | Oil & Gas Operator | Jun 2005 |
| 328 | J O C Operating Inc | Fort Worth, TX 76102-6823 | Oil & Gas Operator | Feb 2021 |
| 329 | Jac-Mac Energy Corporation | Oklahoma City, OK 73170 | Oil & Gas Operator | Feb 2024 |
| 330 | Jaco, Troy Inc. | Sherman, TX 75091 | Oil & Gas Operator | Apr 2024 |
| 331 | Jai Oil | Perry, OK 73077-0873 | Oil & Gas Operator | Jan 2024 |
| 332 | Jakmen Inc | Edmond, OK 73034-5313 | Oil & Gas Operator | Jun 2015 |
| 333 | Jan Oil Company | Oklahoma City, OK 73156 | Oil & Gas Operator | May 2006 |
| 334 | Jay Petroleum Inc | Oklahoma City, OK 73154-0526 | Oil & Gas Operator | Mar 2019 |
| 335 | Jec Operating LLC | Oklahoma City, OK 73114-2717 | Oil & Gas Operator | Jan 2024 |
| 336 | Jeffries Pumping Service Inc | Guthrie, OK 73044-8761 | Oil & Gas Operator | Jan 2024 |
| 337 | Jena Operating Company, Inc. | Dallas, TX 75367 | Oil & Gas Operator | May 2007 |
| 338 | Jet Oil Co12/Ofb See 18649 | | Oil & Gas Operator | Jul 2007 |
| 339 | Johnson Bates Drilling Co Inc | Konawa, OK 74849 | Oil & Gas Operator | Aug 2002 |
| 340 | Johnson Bill M Production Co | Perry, OK 73077-1238 | Oil & Gas Operator | Oct 2018 |
| 341 | Jones Loyd | Perryton, TX 79070-0931 | Oil Operator | Jan 2022 |
| 342 | Jones Loyd Well Serv Co Inc | Perryton, TX 79070 | Oil & Gas Operator | Dec 2005 |
| 343 | K & M Oil Company LLC | Hennessey, OK 73742-0597 | Oil & Gas Operator | Feb 2024 |
| 344 | K S Oil Company Inc | Norman, OK 73072-7480 | Oil & Gas Operator | Feb 2024 |
| 345 | Kahn George Operating Co | Seminole, OK 74818 | Oil & Gas Operator | Nov 2000 |
| 346 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Apr 2024 |
| 347 | Kate F H | Oklahoma City, OK 73122 | Oil & Gas Operator | Jun 2000 |
| 348 | Kato Operating Company | Bristow, OK 74010 | Oil & Gas Operator | Mar 2015 |
| 349 | Keener Oil & Gas Company | Tulsa, OK 74119-4416 | Oil & Gas Operator | Feb 2024 |
| 350 | Keener Oil Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2018 |
| 351 | Kelloil Inc | Fort Worth, TX 76116-5600 | Oil & Gas Operator | Mar 2015 |
| 352 | Kelly Jr Walter A Opr Co | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2014 |
| 353 | Kenworthy Operating Company | Tulsa, OK 74132 | Oil & Gas Operator | May 2009 |
| 354 | Key Energy Corporation | Enid, OK 73702-5349 | Oil & Gas Operator | Oct 2017 |
| 355 | Keystone Gas Corporation | Drumright, OK 7403O | Oil & Gas Operator | Apr 2015 |
| 356 | Kibtec Oil & Gas Inc | Guthrie, OK 73044-1215 | Oil & Gas Operator | Nov 2023 |
| 357 | Kiester Operating Company | Oklahoma City, OK 73101-0705 | Oil & Gas Operator | Feb 2024 |
| 358 | Kingfisher CSG Pullr & Const Inc | Hennessey, OK 73742-0024 | Oil & Gas Operator | Apr 2014 |
| 359 | Kirkpatrick Oil Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2024 |
| 360 | KJR Services LLC | | Oil & Gas Operator | Dec 2023 |
| 361 | Klo LLC | Tulsa, OK 74120-2428 | Oil & Gas Operator | Feb 2024 |
| 362 | Kloberdanz, Paul E. | Oklahoma City, OK 73157 | Oil & Gas Operator | Aug 2021 |
| 363 | Koby Oil Company LLC | Oklahoma City, OK 73101-1945 | Oil & Gas Operator | Jan 2024 |
| 364 | Koda Operating LLC | | Oil & Gas Operator | Jan 2024 |
| 365 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2024 |
| 366 | Kybenco Disposals LLC | | Oil Operator | Sep 2022 |
| 367 | L E Jones Operating Inc | Duncan, OK 73534 | Oil & Gas Operator | Feb 2024 |
| 368 | Ladder Energy Company | Tulsa, OK 74120-4281 | Oil & Gas Operator | Jan 2018 |
| 369 | Lake Country Disposal II LLC | | Oil Operator | Jan 2024 |
| 370 | Lake Country Disposal LLC | | Oil Operator | Jan 2024 |
| 371 | Lakeshore Operating, LLC | Wichita, KS 67203 | Oil & Gas Operator | Apr 2024 |
| 372 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | Jan 2024 |
| 373 | Lance Ruffel Oil & Gas LLC | Oklahoma City, OK 73102-5632 | Oil & Gas Operator | Feb 2024 |
| 374 | Las Colinas Oil Corp. | Irving, TX 75062 | Oil & Gas Operator | Mar 2015 |
| 375 | Lauck & Associates | Walnut Creek, CA 91789 | Oil & Gas Operator | Jan 2024 |
| 376 | Laurel Operating Company, Inc. | Stillwater, OK 74074-3025 | Oil & Gas Operator | Jan 2024 |
| 377 | Lawrence Roy Drilling Co Inc | Pawnee, OK 74058-0306 | Oil & Gas Operator | Aug 2000 |
| 378 | Le Bas Operating Company, Inc. | Giddings, TX 78942 | Oil & Gas Operator | Mar 2000 |
| 379 | Le Norman Energy Corporation | Duncan, OK 73534 | Oil & Gas Operator | Nov 2014 |
| 380 | Leavell Resources Corporation | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 381 | Lee Energy Exploration LTD | Oklahoma City, OK 73102-7114 | Oil & Gas Operator | Jul 2008 |
| 382 | Legacy - M & K Corporation | Dallas, TX 75231-0969 | Oil & Gas Operator | Jan 2024 |
| 383 | Legacy Energy Services LLC | | Oil & Gas Operator | Jan 2024 |
| 384 | Legacy Reserves Operating LP | Denver, CO 80202 | Oil & Gas Operator | Apr 2024 |
| 385 | Leigh Operating Co | Dallas, TX 75205 | Oil & Gas Operator | Mar 2008 |
| 386 | Lewbet Inc | Perry, OK 73077-8914 | Oil & Gas Operator | Jan 2024 |
| 387 | Lewis Oil Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Jan 2024 |
| 388 | Lewis, R. J. Oil Company | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2014 |
| 389 | Likins-Foster Honolulu Corp | Foster City, CA 94404 | Oil & Gas Operator | Feb 2015 |
| 390 | Link Oil Company (The) | Tulsa, OK 74103-4113 | Oil & Gas Operator | Jan 2014 |
| 391 | Lion Petroleum Company | Oklahoma City, OK 73120-4503 | Oil & Gas Operator | Aug 2015 |
| 392 | Little Bear Resources LLC | Stillwater, OK 74074-1388 | Oil & Gas Operator | Feb 2013 |
| 393 | Little River Energy Co. | Drumright, OK 74030 | Oil & Gas Operator | Jan 2024 |
| 394 | Lu-Ray Petroleum LLC | Oklahoma City, OK 73121-1607 | Oil & Gas Operator | Feb 2024 |
| 395 | Luween Energy LLC | | Oil & Gas Operator | Jan 2024 |
| 396 | LVM Oil Production LLC | Yale, OK 74085-6688 | Oil & Gas Operator | Jul 2021 |
| 397 | LX4 LLC | | Oil Operator | Jan 2024 |
| 398 | M E Klein & Associates LLC | Washington, OK 73070-8106 | Oil & Gas Operator | Feb 2024 |
| 399 | M K W Inc | Oklahoma City, OK 73112-8884 | Oil & Gas Operator | Dec 2009 |
| 400 | M M Energy, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Jan 2024 |