| 301 | Inca Oil Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2009 |
| 302 | Indian Oil Company | Gainesville, TX 76241 | Oil & Gas Operator | Apr 2026 |
| 303 | Internorth Inc | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2014 |
| 304 | Investment Equipment LLC | FT Morgan, CO 80701 | Oil & Gas Operator | Jan 2026 |
| 305 | Ip Petroleum Company, Inc. | Houston, TX 77210 | Oil & Gas Operator | Mar 2008 |
| 306 | Irex Corporation | Englewood, CO 80111 | Oil & Gas Operator | May 2000 |
| 307 | Iron Sights Operating, Inc. | Stillwater, OK 74076 | Oil & Gas Operator | Jul 2022 |
| 308 | J & R Transports Inc | Woodward, OK 73802 | Oil & Gas Operator | Dec 2006 |
| 309 | J&R Operating | Holliday, TX 76366 | Oil & Gas Operator | Feb 2024 |
| 310 | J-Brex Company | Amarillo, TX 79101 | Oil & Gas Operator | Apr 2026 |
| 311 | JCS Operating LLC | Guymon, OK 73942 | Oil & Gas Operator | Jan 2026 |
| 312 | Jec Operating LLC | Oklahoma City, OK 73114-2717 | Oil & Gas Operator | Jan 2026 |
| 313 | Jico Exploration Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Nov 2004 |
| 314 | JKB Resources LLC | Stigler, OK 74462 | Oil & Gas Operator | Feb 2026 |
| 315 | Jma Energy Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2026 |
| 316 | Jma Resources Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 2026 |
| 317 | Jo-Allyn Oil Co Inc | Laverne, OK 73848 | Oil & Gas Operator | Jan 2026 |
| 318 | Jones & Pellow Oil Co | Oklahoma City, OK 73118-1115 | Oil & Gas Operator | Feb 2015 |
| 319 | Jones Energy, LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Jan 2026 |
| 320 | Jordan Oil & Gas Company | Healdsburg, CA 95448-1919 | Oil & Gas Operator | Mar 1995 |
| 321 | K D S Resources Co | Thomas, OK 73669 | Oil & Gas Operator | Jan 2026 |
| 322 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Apr 2026 |
| 323 | KC Resources Inc | Snowmass VLG., CO 81615 | Oil & Gas Operator | Jan 2026 |
| 324 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 325 | KCS Resources LLC | Houston, TX 77027 | Oil & Gas Operator | Feb 2017 |
| 326 | Kechi Energy LLC | Chickasha, OK 73018 | Oil & Gas Operator | Jan 2026 |
| 327 | Keith F Walker Oil & Gas Company LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Feb 2026 |
| 328 | Kelly Jr Walter A Opr Co | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2014 |
| 329 | Ken Snyder Inc | Newalla, OK 74857-7107 | Oil & Gas Operator | Jan 2026 |
| 330 | Kennedy & Mitchell, Inc. | Houston, TX 77084 | Oil & Gas Operator | Aug 2013 |
| 331 | Kenneth W Cory LTD | Bellaire, TX 77401 | Oil & Gas Operator | Jan 2026 |
| 332 | Kepco Operating, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Jan 2026 |
| 333 | Kerr McGee Rocky MTN Corp | Denver, CO 80202-5736 | Oil & Gas Operator | Mar 2015 |
| 334 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Feb 2026 |
| 335 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 336 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Apr 2026 |
| 337 | Key Production Company, Inc. | Longview, TX 75606 | Oil & Gas Operator | Feb 2026 |
| 338 | Kibtec Oil & Gas Inc | Cashion, OK 73016 | Oil & Gas Operator | Aug 2024 |
| 339 | King Operating Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Apr 2026 |
| 340 | Kingery Drilling Co., Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Feb 2026 |
| 341 | Kingfisher Resources Inc | Clinton, OK 73601 | Oil & Gas Operator | Feb 2026 |
| 342 | Kirkpatrick Oil Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Apr 2026 |
| 343 | KNG Producers | Dumas, TX 79029 | Oil & Gas Operator | Oct 2009 |
| 344 | Koch Oil Company | | Oil & Gas Operator | May 2017 |
| 345 | Krumme Oil Company LLP | Bristow, OK 74010 | Oil & Gas Operator | Feb 2026 |
| 346 | L & L Smith Energy Corporation | Muskogee, OK 74403-8479 | Oil & Gas Operator | Jan 2023 |
| 347 | Lariat Petroleum Inc | Tulsa, OK 74119 | Oil & Gas Operator | Sep 2024 |
| 348 | Lario Oil & Gas Company | Odessa, TX 79762 | Oil & Gas Operator | Apr 2026 |
| 349 | Larkspur Operating LLC | Oklahoma City, OK 73106 | Oil & Gas Operator | Feb 2026 |
| 350 | Latex Petroleum Corp. | Houston, TX 77090 | Oil & Gas Operator | Aug 2012 |
| 351 | Latigo Oil & Gas, Inc. | Woodward, OK 73801 | Oil & Gas Operator | Feb 2026 |
| 352 | Le Norman Energy Corporation | Duncan, OK 73534 | Oil & Gas Operator | Nov 2014 |
| 353 | Lime Rock Resources II-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2026 |
| 354 | Lincoln Rock Corporation | Northfield, IL 60093 | Oil & Gas Operator | Jul 2003 |
| 355 | Lobo Exploration Company | Yukon, OK 73099 | Oil & Gas Operator | Jan 2026 |
| 356 | Lowry Exploration Inc | Tulsa, OK 74119 | Oil & Gas Operator | Jan 2026 |
| 357 | LX4, LLC | | Oil Operator | Feb 2026 |
| 358 | Mackellar Inc | Oklahoma City, OK 73116-7101 | Oil & Gas Operator | Feb 2026 |
| 359 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 360 | Marathon Oil Company LLC | Houston, TX 77079 | Oil & Gas Operator | Feb 2026 |
| 361 | Mark L Shidler Inc | Houston, TX 77055 | Oil & Gas Operator | Feb 2026 |
| 362 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Feb 2026 |
| 363 | Martin'S Resources LLC | Woodward, OK 73801-5641 | Oil & Gas Operator | Feb 2026 |
| 364 | Matador E & P Company Inc | | Oil & Gas Operator | May 2020 |
| 365 | May Petroleum Inc | Dallas, TX 75231 | Oil & Gas Operator | Nov 1998 |
| 366 | McGee, Tom Corporation | Booker, TX 79005 | Oil & Gas Operator | Jan 2026 |
| 367 | McOr Oil & Gas Corp | Houston, TX 77002 | Oil & Gas Operator | Oct 2013 |
| 368 | Meade Energy Corporation | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | Feb 2026 |
| 369 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Feb 2026 |
| 370 | Medallion Petroleum, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2015 |
| 371 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 372 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2026 |
| 373 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 374 | Metropolitan Resources Corp | Tulsa, OK 74169-1734 | Oil & Gas Operator | Mar 2015 |
| 375 | Mewbourne Marketing, Inc. | | Oil & Gas Operator | Mar 2013 |
| 376 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | Apr 2026 |
| 377 | Mge Resources, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Jan 2026 |
| 378 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 379 | Midway Operating Company, L.L.C. | Woodward, OK 73802 | Oil & Gas Operator | Apr 2026 |
| 380 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 381 | Milmac Operating Company | Lubbock, TX 79408-2976 | Oil & Gas Operator | Sep 2004 |
| 382 | Mito Resources LLC | Edmond, OK 73013 | Oil & Gas Operator | Feb 2026 |
| 383 | Monterey Production Company LLC | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2026 |
| 384 | Moss Ted A Operating Company | Oklahoma City, OK 73126-0187 | Oil & Gas Operator | Jun 1997 |
| 385 | Moss William Properties Inc | Dallas, TX 75219 | Oil & Gas Operator | Apr 2014 |
| 386 | Muras Energy Inc | Edmond, OK 73013 | Oil & Gas Operator | Jan 2026 |
| 387 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 388 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2026 |
| 389 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 390 | Nadel And Gussman LLC | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2026 |
| 391 | National Energy Group Inc | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 392 | Natural Gas Anadarko Company | Perryton, TX 79070 | Oil & Gas Operator | Apr 2026 |
| 393 | Natural Gas Anadarko Inc | Perryton, TX 79070 | Oil & Gas Operator | May 1999 |
| 394 | Neg Operating LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | Aug 2025 |
| 395 | New Horizon Resources LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2026 |
| 396 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Apr 2026 |
| 397 | Noble Energy Production Inc | Houston, TX 77067 | Oil & Gas Operator | Apr 2026 |
| 398 | North American Royalties, Inc. | Chattanooga, TN 37408 | Oil & Gas Operator | Oct 2001 |
| 399 | O G & E | Oklahoma City, OK 73124 | Oil & Gas Operator | Feb 2014 |
| 400 | O K Swabbing Inc | Hennessey, OK 73742 | Oil & Gas Operator | Feb 2026 |