| 301 | Hadson Petro USA Inc | | Oil & Gas Operator | Nov 2016 |
| 302 | Halcon Holdings Inc | Ada, OK 74820 | Oil & Gas Operator | Nov 2018 |
| 303 | Halliburton Oil Producing Co. | Duncan, OK 73534 | Oil & Gas Operator | Apr 2016 |
| 304 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2024 |
| 305 | Hamil Oil & Gas LLC | Kingfisher, OK 73750-6500 | Oil & Gas Operator | Jan 2025 |
| 306 | Harding & Shelton Inc | Oklahoma City, OK 73104-2410 | Oil & Gas Operator | Jan 2025 |
| 307 | Harken Exploration Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2008 |
| 308 | Harrell Verlan W | Oklahoma City, OK 73102-7201 | Oil & Gas Operator | Nov 1999 |
| 309 | Hazelwood Louis J | Albuquerque, NM 87111-6870 | Oil & Gas Operator | Feb 2023 |
| 310 | Hazlewood Oil & Gas Co Inc | Oklahoma City, OK 73139-9353 | Oil & Gas Operator | Apr 2022 |
| 311 | HCM | Dallas, TX 75206 | Oil & Gas Operator | Mar 2015 |
| 312 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 313 | Hegco Canada Inc | | Oil & Gas Operator | Nov 2003 |
| 314 | Helena Resources LLC | Helena, OK 73741-4120 | Oil & Gas Operator | Jan 2025 |
| 315 | Hellard Elmer J | Sapulpa, OK 74066 | Oil & Gas Operator | Jan 2025 |
| 316 | Hennessey Oil & Gas LLC | Hennessey, OK 73742-0212 | Oil & Gas Operator | Sep 2024 |
| 317 | Henry Gungoll Operating Inc | Enid, OK 73703 | Oil & Gas Operator | Feb 2025 |
| 318 | Hep Oil Company LTD | Gainesville, TX 76240 | Oil & Gas Operator | Mar 2012 |
| 319 | Hep Oil GP, LLC | Gainesville, TX 76241 | Oil & Gas Operator | Mar 2015 |
| 320 | Highland Minerals, Inc. | Tulsa, OK 74145-7627 | Oil & Gas Operator | Apr 2015 |
| 321 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Apr 2025 |
| 322 | Hills Dozer Service | Stroud, OK 74079 | Oil & Gas Operator | Mar 2022 |
| 323 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 324 | Hodgden Operating Co., Inc. | Enid, OK 73702 | Oil & Gas Operator | Feb 2025 |
| 325 | Holke Dave Consulting Inc | Meridian, ID 83646-4812 | Oil & Gas Operator | Jan 2025 |
| 326 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Apr 2025 |
| 327 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Oct 2024 |
| 328 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 329 | HPC Incorporated | Denver, CO 80202 | Oil & Gas Operator | Nov 1998 |
| 330 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Apr 2025 |
| 331 | Hughes Gas Systems LLC | Dallas, TX 75214 | Oil & Gas Operator | Jan 2025 |
| 332 | Hugoton Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2019 |
| 333 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Apr 2025 |
| 334 | Husky Ventures Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Jan 2025 |
| 335 | Hux Oil Company LLC | Kingfisher, OK 73750 | Oil & Gas Operator | Jan 2025 |
| 336 | Impact Energy Operating LLC | Oklahoma City, OK 73172 | Oil & Gas Operator | Feb 2025 |
| 337 | Indian Oil Company | Gainesville, TX 76241 | Oil & Gas Operator | Apr 2025 |
| 338 | Indrex Inc | Tulsa, OK 74133 | Oil & Gas Operator | Dec 2000 |
| 339 | Infinity Hydrocarbons LLC | Houston, TX 77079 | Oil & Gas Operator | Aug 2022 |
| 340 | Internorth Inc | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2014 |
| 341 | Investment Equipment LLC | FT Morgan, CO 80701 | Oil & Gas Operator | Jan 2025 |
| 342 | Iron Sights Operating Inc | Stillwater, OK 74076 | Oil & Gas Operator | Jul 2022 |
| 343 | J J B Oil & Gas Inc | Mineral Wells, TX 76068 | Oil & Gas Operator | Nov 1996 |
| 344 | J L Hajek Enterprises LLC | Ames, OK 73718 | Oil & Gas Operator | Dec 2024 |
| 345 | Jack Oil Company | Baird, TX 79504 | Oil & Gas Operator | Feb 2025 |
| 346 | Jackson Petroleum Consult Inc | Dallas, TX 75287 | Oil & Gas Operator | Aug 1994 |
| 347 | January Investments LLC | Norman, OK 73069-8224 | Oil & Gas Operator | Feb 2025 |
| 348 | Jebito Farm LLC | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Jan 2025 |
| 349 | Jec Operating LLC | Oklahoma City, OK 73114-2717 | Oil & Gas Operator | Jan 2025 |
| 350 | Jeda Kini Production Co LLC | Hays, KS 67601-3659 | Oil & Gas Operator | Mar 2008 |
| 351 | Jico Exploration Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Nov 2004 |
| 352 | JKB Resources LLC | Stigler, OK 74462 | Oil & Gas Operator | Jan 2025 |
| 353 | Jma Energy Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2025 |
| 354 | Johnson Exploration Company | Oklahoma City, OK 73102-7008 | Oil & Gas Operator | Jun 2015 |
| 355 | Jones Energy LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Jan 2025 |
| 356 | Jones Oil Company LLC (The) | Duncan, OK 73533-4995 | Oil & Gas Operator | Jan 2025 |
| 357 | Jordan Development Company LLC | Traverse City, MI 49686 | Oil & Gas Operator | Jan 2025 |
| 358 | K & F Oil Co. | Olney, TX 76374 | Oil & Gas Operator | Dec 2021 |
| 359 | K & M Oil Company LLC | Hennessey, OK 73742 | Oil & Gas Operator | Jan 2025 |
| 360 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Apr 2025 |
| 361 | KC Resources Inc | Snowmass VLG., CO 81615 | Oil & Gas Operator | Jan 2025 |
| 362 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 363 | Kerr McGee Rocky MTN Corp | Denver, CO 80202-5736 | Oil & Gas Operator | Mar 2015 |
| 364 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Jan 2025 |
| 365 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 366 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Apr 2025 |
| 367 | Key Energy Services Inc | Midland, TX 79705-5540 | Oil Operator | Jan 2008 |
| 368 | Kibtec Oil & Gas Inc | Cashion, OK 73016 | Oil & Gas Operator | Aug 2024 |
| 369 | Kiester Operating Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Jan 2025 |
| 370 | Kingfisher Resources Inc | Clinton, OK 73601 | Oil & Gas Operator | Feb 2025 |
| 371 | Kirk David | Midland, TX 79705 | Oil & Gas Operator | Jan 2025 |
| 372 | Kirkpatrick Oil Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Apr 2025 |
| 373 | Klingensmith Fred T Etal | Sapulpa, OK 74066 | Oil & Gas Operator | Nov 2007 |
| 374 | Koch Midstream Services Company | Wichita, KS 67201 | Oil & Gas Operator | Oct 2000 |
| 375 | Koch Oil Company | | Oil & Gas Operator | May 2017 |
| 376 | Kodiak Oil & Gas Exploration Inc | Oklahoma City, OK 73134-1046 | Oil & Gas Operator | Jan 2025 |
| 377 | Kodiak Oil & Gas Inc | Muenster, TX 76252 | Oil & Gas Operator | Apr 2025 |
| 378 | KRS Oil Company | Frisco, TX 75034 | Oil & Gas Operator | Apr 2020 |
| 379 | KT Energy Inc | Enid, OK 73702-2365 | Oil & Gas Operator | Jan 2025 |
| 380 | L & B Oil Company Inc | Houston, TX 77019-3115 | Oil & Gas Operator | Jan 2025 |
| 381 | Ladd Petroleum Corp. | Denver, CO 80202 | Oil & Gas Operator | Oct 2004 |
| 382 | Lagoon Water Logistics LLC | Oklahoma City, OK 73103 | Oil Operator | Jul 2024 |
| 383 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | Jan 2025 |
| 384 | Lammerts Robert P | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2002 |
| 385 | Lance Ruffel Oil & Gas LLC | Oklahoma City, OK 73102-5632 | Oil & Gas Operator | Feb 2025 |
| 386 | Lanfield Operating LLC | Owasso, OK 74055-7410 | Oil & Gas Operator | Oct 2022 |
| 387 | Langham Petroleum Expl. Corp. | Houston, TX 77056 | Oil & Gas Operator | Dec 2009 |
| 388 | Latigo Oil And Gas Inc | Woodward, OK 73801 | Oil & Gas Operator | Feb 2025 |
| 389 | Laurel Operating Company, Inc. | Stillwater, OK 74074-3025 | Oil & Gas Operator | Jan 2025 |
| 390 | Lawrence, C. F. & Assoc. Inc. | Lubbock, TX 79401 | Oil & Gas Operator | Apr 2025 |
| 391 | LCB Resources LLC | Kingfisher, OK 73750-2322 | Oil & Gas Operator | Feb 2025 |
| 392 | Le Norman Energy Corporation | Duncan, OK 73534 | Oil & Gas Operator | Nov 2014 |
| 393 | Leavell Resources Corporation | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 394 | Legacy Energy Services LLC | Stillwater, OK 74074 | Oil & Gas Operator | Jan 2025 |
| 395 | Lime Rock Resources II-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2025 |
| 396 | Long Royalty Company | Yukon, OK 73085 | Oil & Gas Operator | Jan 2004 |
| 397 | Longfellow Energy, LP | Dallas, TX 75225 | Oil & Gas Operator | Apr 2025 |
| 398 | Lorentz Oil & Gas LLC | Edmond, OK 73034-7266 | Oil & Gas Operator | Jan 2025 |
| 399 | Louis Dreyfus Gas Marketing | Oklahoma City, OK 73134 | Oil & Gas Operator | Mar 2018 |
| 400 | Lvi Enterprises Trust | Plano, TX 75093-7789 | Oil & Gas Operator | Nov 2014 |