| Boulder to Roy (Utah) | 365.13 mi (587.62 km) |
| Boulder to Royal Kunia (Hawaii) | 3,333.31 mi (5,364.45 km) |
| Boulder to Royal Oak (Michigan) | 1,157.04 mi (1,862.08 km) |
| Boulder to Royal Palm Beach (Florida) | 1,703.29 mi (2,741.18 km) |
| Boulder to Royse City (Texas) | 694.58 mi (1,117.82 km) |
| Boulder to Ruskin (Florida) | 1,554.81 mi (2,502.23 km) |
| Boulder to Russellville (Alabama) | 1,034.08 mi (1,664.19 km) |
| Boulder to Russellville (Arkansas) | 738.58 mi (1,188.63 km) |
| Boulder to Ruston (Louisiana) | 871.33 mi (1,402.27 km) |
| Boulder to Rutherford (New Jersey) | 1,630.57 mi (2,624.15 km) |
| Boulder to Rutland (Vermont) | 1,669.53 mi (2,686.85 km) |
| Boulder to Sabana Grande (Puerto Rico) | 2,733.13 mi (4,398.55 km) |
| Boulder to Sachse (Texas) | 684.50 mi (1,101.60 km) |
| Boulder to Saco (Maine) | 1,795.53 mi (2,889.62 km) |
| Boulder to Sacramento (California) | 871.67 mi (1,402.82 km) |
