| Boulder to River Ridge (Louisiana) | 1,096.21 mi (1,764.17 km) |
| Boulder to Riverbank (California) | 857.64 mi (1,380.24 km) |
| Boulder to Riverdale (Georgia) | 1,232.89 mi (1,984.15 km) |
| Boulder to Riverdale (Illinois) | 926.01 mi (1,490.27 km) |
| Boulder to Riverside (California) | 790.11 mi (1,271.55 km) |
| Boulder to Riverside (Ohio) | 1,117.47 mi (1,798.39 km) |
| Boulder to Riverton (Utah) | 355.35 mi (571.87 km) |
| Boulder to Riverton (Wyoming) | 264.92 mi (426.35 km) |
| Boulder to Riverview (Florida) | 1,555.41 mi (2,503.19 km) |
| Boulder to Riverview (Michigan) | 1,154.75 mi (1,858.40 km) |
| Boulder to Riviera Beach (Florida) | 1,707.13 mi (2,747.36 km) |
| Boulder to Riviera Beach (Maryland) | 1,524.00 mi (2,452.64 km) |
| Boulder to Roanoke (Virginia) | 1,373.27 mi (2,210.07 km) |
| Boulder to Roanoke Rapids (North Carolina) | 1,512.11 mi (2,433.51 km) |
| Boulder to Robbinsdale (Minnesota) | 697.38 mi (1,122.32 km) |
