| Boulder to Corinth (Mississippi) | 980.53 mi (1,578.02 km) |
| Boulder to Corinth (Texas) | 656.85 mi (1,057.10 km) |
| Boulder to Cornelius (North Carolina) | 1,363.44 mi (2,194.25 km) |
| Boulder to Cornelius (Oregon) | 976.60 mi (1,571.69 km) |
| Boulder to Corning (New York) | 1,468.97 mi (2,364.08 km) |
| Boulder to Corona (California) | 801.11 mi (1,289.26 km) |
| Boulder to Coronado (California) | 834.04 mi (1,342.26 km) |
| Boulder to Corpus Christi (Texas) | 961.42 mi (1,547.26 km) |
| Boulder to Corsicana (Texas) | 735.42 mi (1,183.54 km) |
| Boulder to Cortland (New York) | 1,511.80 mi (2,433.01 km) |
| Boulder to Corvallis (Oregon) | 970.83 mi (1,562.39 km) |
| Boulder to Coshocton (Ohio) | 1,232.66 mi (1,983.77 km) |
| Boulder to Costa Mesa (California) | 825.23 mi (1,328.07 km) |
| Boulder to Coto de Caza (California) | 812.92 mi (1,308.27 km) |
| Boulder to Cottage Grove (Minnesota) | 709.43 mi (1,141.71 km) |
