| 1 | U S Energy Corp. Of Amer. Inc. | Ranger, TX 76470 | Oil & Gas Operator | May 2024 |
| 2 | U. D. Man, Inc. | San Antonio, TX 78212 | Oil & Gas Operator | May 2024 |
| 3 | U. S. Operating, Inc. | Dallas, TX 75252 | Oil & Gas Operator | May 2024 |
| 4 | U.S. Enercorp, LLC | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2004 |
| 5 | U.S. Enercorp, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2019 |
| 6 | U.S. Energy Development Corp | Arlington, TX 76011 | Oil & Gas Operator | May 2024 |
| 7 | U.S. Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 8 | U.S. Sovereign Oil And Gas, Inc. | Dallas, TX 75355 | Oil & Gas Operator | May 2024 |
| 9 | U.S.A. Plugging Company | Pearsall, TX 78061 | Oil & Gas Operator | May 2024 |
| 10 | U1 Ranch Oil | Weesatche, TX 77993 | Oil & Gas Operator | May 2024 |
| 11 | Ubetco, Inc. | Rockdale, TX 76567 | Oil & Gas Operator | May 2024 |
| 12 | Uhc Petroleum Corporation | Rocksprings, TX 78880 | Oil & Gas Operator | May 2024 |
| 13 | Ulatex Oil & Gas Inc. | Nocona, TX 76255 | Oil & Gas Operator | Dec 1998 |
| 14 | Ultra Oil & Gas, Inc. | Centerton, AR 72719 | Oil & Gas Operator | May 2024 |
| 15 | Ultra Petroleum (U.S.A.), Inc. | Granbury, TX 76048 | Oil & Gas Operator | Sep 2003 |
| 16 | Ultra Resources Inc | Houston, TX 77060 | Oil & Gas Operator | Feb 2024 |
| 17 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 18 | Unbridled Resources, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2024 |
| 19 | Underwood, Jim | Graham, TX 76450 | Oil & Gas Operator | Mar 2018 |
| 20 | Unicorn Energy, Inc. | Elgin, TX 78621 | Oil & Gas Operator | May 2024 |
| 21 | Unified Oil & Gas Corp. | Snyder, TX 79550 | Oil Operator | May 2024 |
| 22 | Union Crude Company | Baytown, TX 77521 | Oil & Gas Operator | Apr 2018 |
| 23 | Union Crude Operating Co. | Baytown, TX 77521 | Oil Operator | Aug 2003 |
| 24 | Union Gas Operating Company | Houston, TX 77014 | Oil & Gas Operator | May 2024 |
| 25 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 26 | Union Pacific Austin Chalk Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 27 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 28 | Union Royalty, Inc. | Midland, TX 79706 | Oil & Gas Operator | Jul 2014 |
| 29 | Union Seaboard Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 30 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | May 2024 |
| 31 | United Company | Lubbock, TX 79408 | Oil & Gas Operator | Jun 1995 |
| 32 | United Energy Corporation | San Antonio, TX 78209 | Oil & Gas Operator | May 2024 |
| 33 | United Energy Operating, LLC | Edmond, OK 73083 | Oil & Gas Operator | May 2024 |
| 34 | United Energy Partners, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 35 | United Energy Trading LLC | Tulsa, OK 74133 | Gas Operator | Feb 2015 |
| 36 | United Oil & Minerals L. P. | Austin, TX 78746 | Oil & Gas Operator | Jun 2003 |
| 37 | United Oil & Minerals, Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2001 |
| 38 | United Operating Company | Olney, TX 76374 | Oil & Gas Operator | Aug 2003 |
| 39 | United Operating, LLC *** | Midland, TX 79710 | Oil & Gas Operator | May 2024 |
| 40 | United Petroleum & Gas, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | May 2024 |
| 41 | United Petroleum Technologies | Hondo, TX 78861 | Oil & Gas Operator | Aug 2001 |
| 42 | United Production Company LLC | Edmond, OK 73083-5348 | Oil & Gas Operator | Feb 2024 |
| 43 | United Resources LP | Austin, TX 78746 | Oil & Gas Operator | Oct 2011 |
| 44 | United States Gypsum Company | Oakfield, NY 14125 | Oil & Gas Operator | Dec 2022 |
| 45 | United Texas Oil LLC | Houston, TX 77027 | Oil & Gas Operator | May 2024 |
| 46 | United Texas Petroleum Inc. | McKinney, TX 75070 | Oil & Gas Operator | May 2024 |
| 47 | United World Energy, Inc. | Aurora, CO 80040 | Oil & Gas Operator | May 2024 |
| 48 | Unitex Oil & Gas, L.L.C. | Midland, TX 79701 | Oil & Gas Operator | May 2024 |
| 49 | Universal Geopower LLC | Houston, TX 77057 | Oil & Gas Operator | May 2016 |
| 50 | Universal Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2002 |
| 51 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 52 | Unknown | Houston, TX 77208 | Oil & Gas Operator | Dec 2022 |
| 53 | Unocal Exploration Corporation | Houston, TX 77001 | Oil & Gas Operator | May 1992 |
| 54 | Unoso Operating Company L.L.C. | Georgetown, TX 78633 | Oil & Gas Operator | May 2024 |
| 55 | Unswept Oil Company | Corsicana, TX 75151 | Oil & Gas Operator | Jan 2018 |
| 56 | Untamed Resources, LLC | Spearman, TX 79081 | Gas Operator | May 2024 |
| 57 | Uosi Operating, Inc. | Lovelady, TX 75851 | Oil & Gas Operator | May 2024 |
| 58 | Upcurve Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | May 2024 |
| 59 | Upda Operators, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2009 |
| 60 | Upham Oil & Gas Company | Mineral Wells, TX 76068 | Oil & Gas Operator | May 2024 |
| 61 | Upham, Chester R., Jr. | Mineral Wells, TX 76067 | Oil & Gas Operator | Aug 2001 |
| 62 | Upland Exploration, LLC | Boerne, TX 78006 | Oil & Gas Operator | May 2024 |
| 63 | Upland Operating, LLC | Dallas, TX 75226 | Oil & Gas Operator | May 2024 |
| 64 | Upland Production Company | Edmond, OK 73083 | Oil & Gas Operator | May 2024 |
| 65 | Upland Resources LLC | Canadian, TX 79014 | Oil & Gas Operator | May 2024 |
| 66 | Upland Resources, Inc. | Canadian, TX 79014 | Oil & Gas Operator | Dec 2009 |
| 67 | Uplands Resources Inc | Tulsa, OK 74103-4141 | Oil & Gas Operator | Jan 2024 |
| 68 | Uplift Production Company, Inc. | Shamrock, TX 79079 | Oil & Gas Operator | Feb 1999 |
| 69 | Upp Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2024 |
| 70 | Upstream Exploration LLC | Metairie, LA 70002 | Oil & Gas Operator | Jan 2020 |
| 71 | Upstream Properties, LLC | Southlake, TX 76092 | Oil & Gas Operator | May 2024 |
| 72 | Upstream Resource Partners, LLC | Palestine, TX 75803 | Oil Operator | May 2024 |
| 73 | Uptex Operating Inc. | Dallas, TX 75201 | Oil & Gas Operator | May 2011 |
| 74 | Uptex Operating, L.P. | Dallas, TX 75201 | Oil & Gas Operator | May 2010 |
| 75 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | May 2024 |
| 76 | Ursa Operating Company LLC | Denver, CO 80265 | Oil & Gas Operator | Dec 2020 |
| 77 | Ursus Oil And Gas | Tyler, TX 75703 | Oil & Gas Operator | May 2024 |
| 78 | Us Ecology Winnie, LLC | Winnie, TX 77665 | Oil Operator | May 2024 |
| 79 | Us Energy Holdings, LLC | Richardson, TX 75080 | Oil & Gas Operator | May 2024 |
| 80 | Us. Fuels, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | May 2024 |
| 81 | USA Superior Energy LLC | Houston, TX 77077 | Oil Operator | Mar 2010 |
| 82 | USA Tubulars, Inc. | Valley Spring, TX 76885 | Oil & Gas Operator | Dec 1995 |
| 83 | Usfg Oil & Gas, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Dec 2005 |
| 84 | Utility Ventures Company | Pasadena, TX 77504 | Oil & Gas Operator | May 2024 |
| 85 | Utoco, LTD. | Midland, TX 79704 | Oil Operator | May 2024 |
| 86 | Uvalde Energy Co. | Austin, TX 78747 | Oil & Gas Operator | Nov 1994 |