| 29501 | U.S. Steel Mining Co., LLC | | Gas Operator | Oct 2002 |
| 29502 | U.S.A. Plugging Company | Pearsall, TX 78061 | Oil & Gas Operator | May 2024 |
| 29503 | U1 Ranch Oil | Weesatche, TX 77993 | Oil & Gas Operator | May 2024 |
| 29504 | Uae Investco 1 (Estill), LLC | Ravenna, KY 40472 | Oil Operator | Dec 2022 |
| 29505 | Uae Investco 2 (Lee), LLC | Ravenna, KY 40472 | Oil Operator | Dec 2021 |
| 29506 | Ubetco, Inc. | Rockdale, TX 76567 | Oil & Gas Operator | May 2024 |
| 29507 | Uhc New Mexico Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2007 |
| 29508 | Uhc Petroleum Corporation | Rocksprings, TX 78880 | Oil & Gas Operator | May 2024 |
| 29509 | Uhl Oil Co., Inc. | Bradford, PA 16701 | Oil & Gas Operator | Dec 2022 |
| 29510 | Uhl, Robert | Bradford, PA 16701 | Oil & Gas Operator | Dec 2022 |
| 29511 | Uhls, Jimmie J. | Sedan, KS 67361 | Oil Operator | Sep 2019 |
| 29512 | Uinta Oil & Gas | Roosevelt, UT 84066 | Oil & Gas Operator | Nov 1997 |
| 29513 | Uinta Wax Operating, LLC | Fort Worth, TX 76109 | Oil & Gas Operator | Feb 2024 |
| 29514 | Uinta-Taylor Fund, LTD | Roosevelt, UT 84066 | Oil & Gas Operator | Nov 2018 |
| 29515 | Uintah Investors LLC | Orem, UT 84097 | Oil & Gas Operator | Mar 2024 |
| 29516 | Ulatex Oil & Gas Inc. | Nocona, TX 76255 | Oil & Gas Operator | Dec 1998 |
| 29517 | Ullum Oil And Gas Development Corporation, Inc. | Grantsville, WV 26147-0000 | Oil & Gas Operator | Dec 2021 |
| 29518 | Ulrich, William J. Jr.& Connie | | Gas Operator | Dec 2022 |
| 29519 | Ultra Oil & Gas, Inc. | Centerton, AR 72719 | Oil & Gas Operator | May 2024 |
| 29520 | Ultra Petroleum (U.S.A.), Inc. | Granbury, TX 76048 | Oil & Gas Operator | Sep 2003 |
| 29521 | Ultra Production Company, LLC | Cedar Bluff, VA 24609 | Gas Operator | Oct 2014 |
| 29522 | Ultra Resources Inc | Houston, TX 77060 | Oil & Gas Operator | Sep 2018 |
| 29523 | Ultramar Oil & Gas LTD | Houston, TX 77060 | Oil & Gas Operator | Jul 1995 |
| 29524 | Ultramar Production Company | | Oil & Gas Operator | Dec 1991 |
| 29525 | Ulysses, City Of | Ulysses, KS 67880 | Gas Operator | Jan 2024 |
| 29526 | Umberham Oil Company Inc | Oklahoma City, OK 73151-4000 | Oil & Gas Operator | Jan 2024 |
| 29527 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 29528 | Ummel'S Tank Ser | | Oil Operator | Sep 1994 |
| 29529 | Unbridled Resources, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2024 |
| 29530 | Underground Energy Inc. | | Oil & Gas Operator | Feb 2024 |
| 29531 | Underwood Oil & Gas | Casper, WY 82602 | Oil & Gas Operator | Mar 2024 |
| 29532 | Underwood Oil And Gas LLC | | Oil & Gas Operator | Feb 2024 |
| 29533 | Underwood, Donald D. Dba Mustang Oil Co | Salem, WV 26426 | Oil & Gas Operator | Dec 2020 |
| 29534 | Underwood, Jim | Graham, TX 76450 | Oil & Gas Operator | Mar 2018 |
| 29535 | Uni Production Company, Inc. | | Oil & Gas Operator | Apr 1988 |
| 29536 | Unicorn Drilling Inc | Cody, WY 82414 | Oil Operator | Dec 1998 |
| 29537 | Unicorn Energy, Inc. | Elgin, TX 78621 | Oil & Gas Operator | May 2024 |
| 29538 | Unicorn Oil & Gas Co Inc | Dorset, OH 44032 | Oil & Gas Operator | Dec 1993 |
| 29539 | Unifid Oil & Gas Corp. | | Oil & Gas Operator | Mar 1994 |
| 29540 | Unified Oil & Gas Corp. | Snyder, TX 79550 | Oil Operator | May 2024 |
| 29541 | Unioil | Denver, CO 80203 | Oil & Gas Operator | Jun 2012 |
| 29542 | Union City Boro Muni Auth Erie Cnty | Union City, PA 16438-1326 | Gas Operator | Dec 2023 |
| 29543 | Union Crude Company | Baytown, TX 77521 | Oil & Gas Operator | Apr 2018 |
| 29544 | Union Crude Operating Co. | Baytown, TX 77521 | Oil Operator | Aug 2003 |
| 29545 | Union Development Company Inc | | Oil & Gas Operator | Dec 1992 |
| 29546 | Union Diversified, Inc. | | Gas Operator | Dec 2008 |
| 29547 | Union Exploration Partners, LTD. | | Oil & Gas Operator | Aug 1990 |
| 29548 | Union Gas Operating Company | Houston, TX 77014 | Oil & Gas Operator | May 2024 |
| 29549 | Union Oil Co | Danville, OH 43014 | Oil & Gas Operator | Dec 2014 |
| 29550 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 29551 | Union Operating Corp | Lakewoord, CO 80215 | Oil Operator | Dec 2022 |
| 29552 | Union Pacific Austin Chalk Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 29553 | Union Pacific Re | | Oil & Gas Operator | Dec 1996 |
| 29554 | Union Pacific Resour | | Oil & Gas Operator | Apr 2002 |
| 29555 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 29556 | Union Petro Inc | Uniontown, KY 42461 | Oil Operator | Dec 2022 |
| 29557 | Union Petrochemical | | Oil & Gas Operator | Dec 1982 |
| 29558 | Union Resources Inc | | Oil & Gas Operator | Dec 1996 |
| 29559 | Union Royalty, Inc. | Midland, TX 79706 | Oil & Gas Operator | Jul 2014 |
| 29560 | Union Seaboard Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 29561 | Union Springs Central School District | Union Springs, NY 13160 | Gas Operator | Dec 2022 |
| 29562 | Union Texas Petroleum | Houston, TX 77252 | Oil & Gas Operator | Oct 1991 |
| 29563 | Union Texas Petroleum Corp. | Houston, TX 77252-2120 | Oil & Gas Operator | Dec 2014 |
| 29564 | Union Texas Products Corp | Houston, TX 77252 | Oil & Gas Operator | Nov 1994 |
| 29565 | Union Valley Petroleum Corporation | Enid, OK 73701 | Oil & Gas Operator | Feb 2024 |
| 29566 | Unionville Explo | | Oil Operator | Jul 1984 |
| 29567 | Unit Drilling & Exploration Co | Tulsa, OK 74132-5300 | Oil & Gas Operator | Dec 2023 |
| 29568 | Unit Manager, Citronelle Unit | | Oil & Gas Operator | Sep 2001 |
| 29569 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | May 2024 |
| 29570 | United Company | Lubbock, TX 79408 | Oil & Gas Operator | Jun 1995 |
| 29571 | United Energy & Expl Inc | Ada, OK 74821-2449 | Oil & Gas Operator | Jan 2024 |
| 29572 | United Energy & Exploration LLC | Ada, OK 74821 | Oil & Gas Operator | Jan 2024 |
| 29573 | United Energy Corporation | San Antonio, TX 78209 | Oil & Gas Operator | May 2024 |
| 29574 | United Energy Develop Co LTD | Bartlesville, OK 74003 | Oil Operator | Mar 2004 |
| 29575 | United Energy Inc. | Wichita, KS 67230 | Oil & Gas Operator | Dec 2002 |
| 29576 | United Energy Operating, LLC | Edmond, OK 73083 | Oil & Gas Operator | May 2024 |
| 29577 | United Energy Partners, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 29578 | United Energy Trading LLC | Tulsa, OK 74133 | Gas Operator | Feb 2015 |
| 29579 | United Fuel Gas Co | | Oil & Gas Operator | Dec 2022 |
| 29580 | United Gas Pipe Line Co. | | Oil Operator | Aug 1993 |
| 29581 | United Investment Group | | Oil Operator | Nov 2004 |
| 29582 | United Meridian | | Oil Operator | Dec 1992 |
| 29583 | United Natural Gas LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2020 |
| 29584 | United Natural Resources Corp | | Oil Operator | Jan 1986 |
| 29585 | United O&G/Atlee Miller | Millersburg, OH 44654 | Oil & Gas Operator | Dec 1985 |
| 29586 | United Oil & Gas | | Oil Operator | Feb 1988 |
| 29587 | United Oil & Minerals L. P. | Austin, TX 78746 | Oil & Gas Operator | Jun 2003 |
| 29588 | United Oil & Minerals, Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2001 |
| 29589 | United Oil Corporation | Denver, CO 80202-3813 | Oil & Gas Operator | Jan 2024 |
| 29590 | United Operating Company | Olney, TX 76374 | Oil & Gas Operator | Aug 2003 |
| 29591 | United Operating, LLC *** | Midland, TX 79710 | Oil & Gas Operator | May 2024 |
| 29592 | United Operators, Inc. | | Oil Operator | Sep 1999 |
| 29593 | United Petro LTD. | | Oil & Gas Operator | Dec 2018 |
| 29594 | United Petroleum | | Oil Operator | Mar 1986 |
| 29595 | United Petroleum & Gas, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | May 2024 |
| 29596 | United Petroleum Corporation | Edgwater, CO 80214 | Oil & Gas Operator | May 1996 |
| 29597 | United Petroleum Technologies | Hondo, TX 78861 | Oil & Gas Operator | Aug 2001 |
| 29598 | United Primary Resources Inc | Milton, WA 98354-9361 | Oil & Gas Operator | Feb 2016 |
| 29599 | United Producers Inc | Broken Arrow, OK 74012-8247 | Oil & Gas Operator | Mar 2020 |
| 29600 | United Producing Co Inc | | Oil & Gas Operator | May 1961 |