| Boulder to Robertsville (New Jersey) | 1,625.94 mi (2,616.70 km) |
| Boulder to Robinson (Texas) | 746.93 mi (1,202.07 km) |
| Boulder to Robstown (Texas) | 949.44 mi (1,527.98 km) |
| Boulder to Rochester (Michigan) | 1,159.06 mi (1,865.33 km) |
| Boulder to Rochester (Minnesota) | 710.34 mi (1,143.18 km) |
| Boulder to Rochester (New Hampshire) | 1,770.97 mi (2,850.10 km) |
| Boulder to Rochester (New York) | 1,437.70 mi (2,313.76 km) |
| Boulder to Rochester Hills (Michigan) | 1,157.17 mi (1,862.28 km) |
| Boulder to Rock Hill (South Carolina) | 1,369.28 mi (2,203.64 km) |
| Boulder to Rock Island (Illinois) | 773.39 mi (1,244.65 km) |
| Boulder to Rock Springs (Wyoming) | 234.14 mi (376.81 km) |
| Boulder to Rockford (Illinois) | 854.99 mi (1,375.98 km) |
| Boulder to Rockledge (Florida) | 1,610.03 mi (2,591.09 km) |
| Boulder to Rocklin (California) | 856.83 mi (1,378.94 km) |
| Boulder to Rockport (Texas) | 950.98 mi (1,530.45 km) |
