| South Portland to Carlsbad (California) | 2,609.38 mi (4,199.39 km) |
| South Portland to Carlsbad (New Mexico) | 1,986.84 mi (3,197.51 km) |
| South Portland to Carmel (Indiana) | 853.56 mi (1,373.68 km) |
| South Portland to Carmichael (California) | 2,636.36 mi (4,242.80 km) |
| South Portland to Carney (Maryland) | 434.82 mi (699.77 km) |
| South Portland to Carnot-Moon (Pennsylvania) | 552.26 mi (888.78 km) |
| South Portland to Carol Stream (Illinois) | 910.75 mi (1,465.72 km) |
| South Portland to Carolina (Puerto Rico) | 1,760.88 mi (2,833.86 km) |
| South Portland to Carolina Forest (South Carolina) | 824.13 mi (1,326.30 km) |
| South Portland to Carpentersville (Illinois) | 915.51 mi (1,473.37 km) |
| South Portland to Carpinteria (California) | 2,677.45 mi (4,308.94 km) |
| South Portland to Carrboro (North Carolina) | 707.46 mi (1,138.54 km) |
| South Portland to Carroll (Iowa) | 1,244.93 mi (2,003.52 km) |
| South Portland to Carrollton (Georgia) | 1,055.46 mi (1,698.60 km) |
| South Portland to Carrollton (Texas) | 1,609.42 mi (2,590.12 km) |
