| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | U. S. Operating, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Mar 2025 |
| 2 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 3 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 4 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2025 |
| 5 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 6 | Ursus Oil And Gas | Tyler, TX 75703 | Oil & Gas Operator | Mar 2025 |
| 7 | Usfg Oil & Gas, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Dec 2005 |