| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | U-N-I Exploratio | Oil & Gas Operator | Dec 1990 | |
| 2 | U-N-I Exploration & Development, Inc. | Yates Center, KS 66783 | Oil & Gas Operator | Jan 2003 |
| 3 | United Oil & Gas | Oil Operator | Feb 1988 | |
| 4 | United States Exploration, Inc. | Denver, CO 80802 | Oil & Gas Operator | Jun 2009 |
| 5 | Unknown | Houston, TX 77208 | Oil & Gas Operator | Dec 2023 |
| 6 | Uranus, Inc. | Kansas City, MO 64112 | Oil Operator | Jan 2000 |
| 7 | Usx Operating Co., Inc. | Barnstall, OK 74002 | Oil & Gas Operator | Apr 2017 |