| 29901 | Tyler Enterprises Inc | Bristow, OK 74010-3192 | Oil & Gas Operator | Feb 2004 |
| 29902 | Tyler Oil & Gas Inc. | Tyler, TX 75702 | Oil & Gas Operator | Sep 2004 |
| 29903 | Tyler Oil Company | Billings, MT 59104-3203 | Oil & Gas Operator | Nov 2019 |
| 29904 | Tyler Production, LLC | | Oil & Gas Operator | Jul 2013 |
| 29905 | Tyler Rockies Exploration LTD | Tyler, TX 75710-0119 | Oil & Gas Operator | Dec 2025 |
| 29906 | Tyler, Scott A | | Oil & Gas Operator | Apr 2026 |
| 29907 | Tyler, Steven Lee | | Oil Operator | May 2014 |
| 29908 | Tyluka Operations, LLC | Hays, KS 67601 | Oil Operator | Mar 2026 |
| 29909 | Tyner Texas Operating Company | Dallas, TX 75248 | Oil & Gas Operator | Jul 2026 |
| 29910 | Tyrex Oil Company | Casper, WY 82602 | Oil & Gas Operator | May 1997 |
| 29911 | Tyro Oil Develop | | Oil Operator | Jul 1991 |
| 29912 | Tyrok | | Oil & Gas Operator | Nov 2010 |
| 29913 | Tysco Oil And Gas Corp. | | Oil & Gas Operator | Dec 2024 |
| 29914 | Tyson Gary | Hobart, OK 73651-6413 | Oil & Gas Operator | Mar 2018 |
| 29915 | Tyson Oil Co. | | Oil Operator | Jan 2025 |
| 29916 | Tyson Olan | Hobart, OK 73651-6413 | Oil & Gas Operator | Apr 2015 |
| 29917 | Tytan Operating Company LLC | Edmond, OK 73083-3794 | Oil & Gas Operator | May 2016 |
| 29918 | U Bee Tea Production LLC | Culbertson, MT 59218 | Oil & Gas Operator | Mar 2026 |
| 29919 | U R C C | | Oil & Gas Operator | Jun 1991 |
| 29920 | U S Drilling Company Inc | Holdenville, OK 74848-0913 | Oil & Gas Operator | Mar 2017 |
| 29921 | U S Energy Corp. Of Amer. Inc. | Cisco, TX 76437 | Oil & Gas Operator | Jul 2026 |
| 29922 | U S Exploraton Liq Trust | | Oil & Gas Operator | Oct 1994 |
| 29923 | U S Liquids Of La., L.P. | | Oil Operator | Apr 2014 |
| 29924 | U V Industries | | Oil & Gas Operator | Jan 1993 |
| 29925 | U-N-I Exploratio | | Oil & Gas Operator | Dec 1990 |
| 29926 | U-N-I Exploration & Development, Inc. | Yates Center, KS 66783 | Oil & Gas Operator | Jan 2003 |
| 29927 | U. D. Man, Inc. | San Antonio, TX 78212 | Oil & Gas Operator | Jul 2026 |
| 29928 | U. O. C., Inc. | | Oil Operator | Jun 2019 |
| 29929 | U. S. Energy Development Corporation | Fort Worth, TX 76164 | Oil & Gas Operator | Jul 2026 |
| 29930 | U. S. Operating, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Jul 2025 |
| 29931 | U.S. Capital Corp Of Am, Inc. | | Oil & Gas Operator | Aug 1998 |
| 29932 | U.S. Enercorp, LLC | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2004 |
| 29933 | U.S. Enercorp, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2019 |
| 29934 | U.S. Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 29935 | U.S. Oil Reclaimers, LLC | | Oil Operator | Jun 2023 |
| 29936 | U.S. Sovereign Oil And Gas, Inc. | Dallas, TX 75355 | Oil & Gas Operator | Jul 2026 |
| 29937 | U.S. Steel Mining Co., Inc. | | Gas Operator | Jan 2000 |
| 29938 | U.S. Steel Mining Co., LLC | | Gas Operator | Oct 2002 |
| 29939 | U.S.A. Plugging Company | Pearsall, TX 78061 | Oil & Gas Operator | Jul 2026 |
| 29940 | U1 Ranch Oil | Houston, TX 77269 | Oil & Gas Operator | Jul 2026 |
| 29941 | Uae Investco 1 (Estill), LLC | Ravenna, KY 40472 | Oil Operator | Dec 2022 |
| 29942 | Uae Investco 2 (Lee), LLC | Ravenna, KY 40472 | Oil Operator | Dec 2021 |
| 29943 | Ubetco, Inc. | Rockdale, TX 76567 | Oil & Gas Operator | Jul 2026 |
| 29944 | Uehlin LLC | Oberlin, KS 67749 | Oil Operator | Jul 2025 |
| 29945 | Uhc New Mexico Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2007 |
| 29946 | Uhc Petroleum Corporation | Rocksprings, TX 78880 | Oil & Gas Operator | Jul 2026 |
| 29947 | Uhl Oil Co., Inc. | Bradford, PA 16701 | Oil & Gas Operator | Dec 2025 |
| 29948 | Uhls, Jimmie J. | Sedan, KS 67361 | Oil Operator | Sep 2019 |
| 29949 | Uinta Oil & Gas | Roosevelt, UT 84066 | Oil & Gas Operator | Nov 1997 |
| 29950 | Uinta Wax Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | May 2026 |
| 29951 | Uintah Investors LLC | Vernal, UT 84078 | Oil & Gas Operator | May 2026 |
| 29952 | Ulatex Oil & Gas Inc. | Nocona, TX 76255 | Oil & Gas Operator | Dec 1998 |
| 29953 | Ulrich, William J., Jr. & Connie K. | Elma, NY 14059 | Gas Operator | Dec 2025 |
| 29954 | Ultra Oil & Gas, Inc. | Centerton, AR 72719 | Oil & Gas Operator | Jul 2026 |
| 29955 | Ultra Petroleum (U.S.A.), Inc. | Granbury, TX 76048 | Oil & Gas Operator | Sep 2003 |
| 29956 | Ultra Production Company, LLC | Cedar Bluff, VA 24609 | Gas Operator | Oct 2014 |
| 29957 | Ultra Resources Inc | Houston, TX 77060 | Oil & Gas Operator | Sep 2018 |
| 29958 | Ultramar Oil & Gas LTD | Houston, TX 77060 | Oil & Gas Operator | Jul 1995 |
| 29959 | Ultramar Production Company | | Oil & Gas Operator | Dec 1991 |
| 29960 | Ulysses, City Of | Ulysses, KS 67880 | Gas Operator | Mar 2026 |
| 29961 | Umad LLC | | Oil & Gas Operator | Feb 2010 |
| 29962 | Umberham Oil Company Inc | Oklahoma City, OK 73151-4000 | Oil & Gas Operator | Apr 2026 |
| 29963 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 29964 | Umma Resources, LLC | Portland, TX 78374 | Gas Operator | Jul 2026 |
| 29965 | Ummel'S Tank Ser | | Oil Operator | Sep 1994 |
| 29966 | Unbridled Resources, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2026 |
| 29967 | Unc Texas Incorp | | Gas Operator | May 1987 |
| 29968 | Underground Energy Inc. | | Oil & Gas Operator | Dec 2025 |
| 29969 | Underwood Oil & Gas | Casper, WY 82602 | Oil & Gas Operator | Jun 2026 |
| 29970 | Underwood Oil And Gas LLC | Chandler, OK 74834-1414 | Oil & Gas Operator | May 2026 |
| 29971 | Underwood, Donald D. Dba Mustang Oil Co | Salem, WV 26426 | Oil & Gas Operator | Dec 2020 |
| 29972 | Underwood, Jim | Graham, TX 76450 | Oil & Gas Operator | Mar 2018 |
| 29973 | Unger Well Drilling Corp | Dennison, OH 44621 | Oil & Gas Operator | Dec 1999 |
| 29974 | Uni Production Company, Inc. | | Oil & Gas Operator | Apr 1988 |
| 29975 | Unicon Producing Company | Houston, TX 75252 | Gas Operator | Mar 1994 |
| 29976 | Unicorn Drilling Inc | Cody, WY 82414 | Oil Operator | Dec 1998 |
| 29977 | Unicorn Energy, Inc. | Elgin, TX 78621 | Oil & Gas Operator | Jul 2026 |
| 29978 | Unicorn Oil & Gas Co Inc | Dorset, OH 44032 | Oil & Gas Operator | Dec 1993 |
| 29979 | Unifid Oil & Gas Corp. | | Oil & Gas Operator | Mar 1994 |
| 29980 | Unified Oil & Gas Corp. | Snyder, TX 79550 | Oil Operator | Jul 2026 |
| 29981 | Unioil | Denver, CO 80203 | Oil & Gas Operator | Dec 2010 |
| 29982 | Union Camp Corp | Dover, OH 44622 | Oil & Gas Operator | Dec 2002 |
| 29983 | Union City Boro Muni Auth Erie Cnty | Union City, PA 16438-1326 | Gas Operator | Dec 2024 |
| 29984 | Union Crude Company | Baytown, TX 77521 | Oil & Gas Operator | Apr 2018 |
| 29985 | Union Crude Operating Co. | Baytown, TX 77521 | Oil Operator | Aug 2003 |
| 29986 | Union Development Company Inc | | Oil & Gas Operator | Dec 1992 |
| 29987 | Union Diversified, Inc. | | Gas Operator | Dec 2008 |
| 29988 | Union Drilling &Management Inc | | Gas Operator | Feb 1991 |
| 29989 | Union Expl. Partners, LTD. | | Oil & Gas Operator | Aug 1990 |
| 29990 | Union Gas Operating Company | Spring, TX 77391 | Oil & Gas Operator | Jul 2026 |
| 29991 | Union Oil Co | Danville, OH 43014 | Oil & Gas Operator | Dec 2014 |
| 29992 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 29993 | Union Operating Corp | Lakewoord, CO 80215 | Oil Operator | Dec 2023 |
| 29994 | Union Pacific Austin Chalk Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 29995 | Union Pacific Re | | Oil & Gas Operator | Dec 1996 |
| 29996 | Union Pacific Resour | | Oil & Gas Operator | Apr 2002 |
| 29997 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 29998 | Union Petro Inc | Uniontown, KY 42461 | Oil Operator | Dec 2024 |
| 29999 | Union Petrochemical | | Oil & Gas Operator | Dec 1982 |
| 30000 | Union Producing Co. | | Gas Operator | Dec 1992 |