| South Portland to Cibolo (Texas) | 1,815.07 mi (2,921.08 km) |
| South Portland to Cicero (Illinois) | 893.39 mi (1,437.77 km) |
| South Portland to Cimarron Hills (Colorado) | 1,804.38 mi (2,903.87 km) |
| South Portland to Cincinnati (Ohio) | 798.25 mi (1,284.66 km) |
| South Portland to Cinco Ranch (Texas) | 1,695.60 mi (2,728.81 km) |
| South Portland to Circleville (Ohio) | 708.88 mi (1,140.82 km) |
| South Portland to Citrus (California) | 2,605.77 mi (4,193.59 km) |
| South Portland to Citrus Heights (California) | 2,632.68 mi (4,236.89 km) |
| South Portland to Citrus Park (Florida) | 1,272.73 mi (2,048.26 km) |
| South Portland to Claiborne (Louisiana) | 1,409.89 mi (2,268.99 km) |
| South Portland to Claremont (California) | 2,596.75 mi (4,179.07 km) |
| South Portland to Claremont (New Hampshire) | 104.06 mi (167.47 km) |
| South Portland to Claremore (Oklahoma) | 1,425.90 mi (2,294.77 km) |
| South Portland to Clarksburg (Maryland) | 472.26 mi (760.03 km) |
| South Portland to Clarksburg (West Virginia) | 599.43 mi (964.69 km) |
