| Boulder to San Diego (California) | 824.87 mi (1,327.50 km) |
| Boulder to San Diego Country Estates (California) | 802.11 mi (1,290.87 km) |
| Boulder to San Dimas (California) | 802.81 mi (1,291.99 km) |
| Boulder to San Fernando (California) | 825.88 mi (1,329.13 km) |
| Boulder to San Francisco (California) | 936.26 mi (1,506.76 km) |
| Boulder to San Gabriel (California) | 817.07 mi (1,314.95 km) |
| Boulder to San Germán (Puerto Rico) | 2,729.17 mi (4,392.17 km) |
| Boulder to San Jacinto (California) | 777.24 mi (1,250.85 km) |
| Boulder to San Jose (California) | 913.46 mi (1,470.07 km) |
| Boulder to San Juan (Puerto Rico) | 2,763.11 mi (4,446.79 km) |
| Boulder to San Juan (Texas) | 1,039.53 mi (1,672.96 km) |
| Boulder to San Juan Capistrano (California) | 820.01 mi (1,319.68 km) |
| Boulder to San Leandro (California) | 922.09 mi (1,483.97 km) |
| Boulder to San Lorenzo (California) | 921.31 mi (1,482.70 km) |
| Boulder to San Luis (Arizona) | 739.77 mi (1,190.55 km) |
