| South Portland to Cordele (Georgia) | 1,089.10 mi (1,752.74 km) |
| South Portland to Corinth (Mississippi) | 1,140.65 mi (1,835.69 km) |
| South Portland to Corinth (Texas) | 1,611.35 mi (2,593.22 km) |
| South Portland to Cornelius (North Carolina) | 796.34 mi (1,281.58 km) |
| South Portland to Cornelius (Oregon) | 2,552.72 mi (4,108.21 km) |
| South Portland to Corning (New York) | 357.44 mi (575.24 km) |
| South Portland to Corona (California) | 2,598.15 mi (4,181.32 km) |
| South Portland to Coronado (California) | 2,619.33 mi (4,215.40 km) |
| South Portland to Corpus Christi (Texas) | 1,861.74 mi (2,996.18 km) |
| South Portland to Corsicana (Texas) | 1,625.72 mi (2,616.34 km) |
| South Portland to Cortland (New York) | 305.36 mi (491.43 km) |
| South Portland to Corvallis (Oregon) | 2,582.67 mi (4,156.40 km) |
| South Portland to Coshocton (Ohio) | 637.28 mi (1,025.60 km) |
| South Portland to Costa Mesa (California) | 2,622.21 mi (4,220.04 km) |
| South Portland to Coto de Caza (California) | 2,608.26 mi (4,197.58 km) |
