| Difficult Run to University Place (Washington) | 2,318.36 mi (3,731.03 km) |
| Difficult Run to Upland (California) | 2,244.65 mi (3,612.42 km) |
| Difficult Run to Upper Arlington (Ohio) | 314.97 mi (506.90 km) |
| Difficult Run to Upper Grand Lagoon (Florida) | 768.82 mi (1,237.30 km) |
| Difficult Run to Upper Montclair (New Jersey) | 214.07 mi (344.51 km) |
| Difficult Run to Urbana (Illinois) | 584.04 mi (939.92 km) |
| Difficult Run to Urbana (Maryland) | 29.42 mi (47.35 km) |
| Difficult Run to Urbana (Ohio) | 351.50 mi (565.69 km) |
| Difficult Run to Urbandale (Iowa) | 885.31 mi (1,424.77 km) |
| Difficult Run to Utica (New York) | 310.18 mi (499.18 km) |
| Difficult Run to Uvalde (Texas) | 1,442.41 mi (2,321.33 km) |
| Difficult Run to Vacaville (California) | 2,384.10 mi (3,836.84 km) |
| Difficult Run to Vadnais Heights (Minnesota) | 910.75 mi (1,465.71 km) |
| Difficult Run to Vail (Arizona) | 1,924.30 mi (3,096.86 km) |
| Difficult Run to Valdosta (Georgia) | 649.64 mi (1,045.49 km) |
