| Difficult Run to Rockville (Maryland) | 16.24 mi (26.14 km) |
| Difficult Run to Rockville Centre (New York) | 231.51 mi (372.58 km) |
| Difficult Run to Rockwall (Texas) | 1,142.80 mi (1,839.15 km) |
| Difficult Run to Rocky Mount (North Carolina) | 204.20 mi (328.63 km) |
| Difficult Run to Rocky Point (New York) | 272.68 mi (438.83 km) |
| Difficult Run to Rocky River (Ohio) | 296.67 mi (477.44 km) |
| Difficult Run to Roessleville (New York) | 321.26 mi (517.02 km) |
| Difficult Run to Rogers (Arkansas) | 935.63 mi (1,505.74 km) |
| Difficult Run to Rogers (Minnesota) | 936.86 mi (1,507.73 km) |
| Difficult Run to Rohnert Park (California) | 2,422.40 mi (3,898.48 km) |
| Difficult Run to Rolla (Missouri) | 782.18 mi (1,258.80 km) |
| Difficult Run to Rolling Meadows (Illinois) | 601.89 mi (968.65 km) |
| Difficult Run to Roma (Texas) | 1,520.47 mi (2,446.95 km) |
| Difficult Run to Rome (Georgia) | 539.78 mi (868.69 km) |
| Difficult Run to Rome (New York) | 314.02 mi (505.37 km) |
