| Difficult Run to Robertsville (New Jersey) | 190.44 mi (306.49 km) |
| Difficult Run to Robinson (Texas) | 1,226.20 mi (1,973.38 km) |
| Difficult Run to Robstown (Texas) | 1,396.58 mi (2,247.57 km) |
| Difficult Run to Rochester (Michigan) | 399.29 mi (642.59 km) |
| Difficult Run to Rochester (Minnesota) | 857.77 mi (1,380.45 km) |
| Difficult Run to Rochester (New Hampshire) | 449.48 mi (723.36 km) |
| Difficult Run to Rochester (New York) | 295.11 mi (474.94 km) |
| Difficult Run to Rochester Hills (Michigan) | 399.78 mi (643.38 km) |
| Difficult Run to Rock Hill (South Carolina) | 340.69 mi (548.29 km) |
| Difficult Run to Rock Island (Illinois) | 720.01 mi (1,158.74 km) |
| Difficult Run to Rock Springs (Wyoming) | 1,681.53 mi (2,706.15 km) |
| Difficult Run to Rockford (Illinois) | 656.48 mi (1,056.51 km) |
| Difficult Run to Rockledge (Florida) | 756.49 mi (1,217.45 km) |
| Difficult Run to Rocklin (California) | 2,338.68 mi (3,763.74 km) |
| Difficult Run to Rockport (Texas) | 1,357.96 mi (2,185.43 km) |
