| U.S. Airmail in Wyoming | Steve Wolff |
| U.S. Bureau of Reclamation in Wyoming | Phil Roberts |
| U.S. Marines invade Teapot Dome | Carolynne Harris |
| Uinta County Courthouse | |
| Uinta County Museum | |
| Uinta County, Wyoming | Barbara Allen Bogart |
| Union Pacific Depot, Cheyenne | |
| Union Pacific Depots | |
| Union Pacific Ice Ponds | |
| Union Pacific in Wyoming, The | Gregory Nickerson |
| Union Pacific Roundhouse and Railyards Complex | |
| United Air Lines stewardess school, Cheyenne | Michael Kassel, Starley Talbott |
| United Airlines Flight 409, 1955 crash of | Thaddeus Mast |
| University of Wyoming Agricultural Experiment Station | |
| University of Wyoming Anthropology Department Museum | |
| University of Wyoming Athletics Hall of Fame | |
| University of Wyoming Geological Museum | |
| University of Wyoming Textbook Controversy | Phil Roberts |
| Unthank, Alvah grave, Oregon Trail site of | Randy Brown |
| Upton Chamber of Commerce | |
| Upton Old Town | |
| Upton, Wyoming | Nicole Lebsack |
| Uranium business, history of in Wyoming | Chamois L. Andersen, Lori Van Pelt |
| Utah War, 1857-1858 | Rebecca Hein |
| Utes, 1906 flight of through Wyoming | Tom Rea |
