| South Portland to Cadillac (Michigan) | 752.73 mi (1,211.41 km) |
| South Portland to Caguas (Puerto Rico) | 1,772.28 mi (2,852.21 km) |
| South Portland to Cahokia (Illinois) | 1,089.98 mi (1,754.15 km) |
| South Portland to Calabasas (California) | 2,644.02 mi (4,255.14 km) |
| South Portland to Caldwell (Idaho) | 2,287.60 mi (3,681.54 km) |
| South Portland to Caledonia (Wisconsin) | 885.78 mi (1,425.52 km) |
| South Portland to Calera (Alabama) | 1,145.75 mi (1,843.91 km) |
| South Portland to Calexico (California) | 2,535.32 mi (4,080.21 km) |
| South Portland to Calhoun (Georgia) | 1,005.60 mi (1,618.35 km) |
| South Portland to California (Maryland) | 490.26 mi (789.00 km) |
| South Portland to California City (California) | 2,570.57 mi (4,136.93 km) |
| South Portland to Callaway (Florida) | 1,253.41 mi (2,017.17 km) |
| South Portland to Calumet City (Illinois) | 886.91 mi (1,427.34 km) |
| South Portland to Calverton (Maryland) | 467.86 mi (752.95 km) |
| South Portland to Camano (Washington) | 2,479.59 mi (3,990.52 km) |
