| South Portland to Cloverleaf (Texas) | 1,667.00 mi (2,682.77 km) |
| South Portland to Cloverly (Maryland) | 467.46 mi (752.30 km) |
| South Portland to Clovis (California) | 2,608.32 mi (4,197.69 km) |
| South Portland to Clovis (New Mexico) | 1,862.08 mi (2,996.73 km) |
| South Portland to Clute (Texas) | 1,712.52 mi (2,756.03 km) |
| South Portland to Coachella (California) | 2,532.87 mi (4,076.26 km) |
| South Portland to Coalinga (California) | 2,661.39 mi (4,283.09 km) |
| South Portland to Coamo (Puerto Rico) | 1,780.40 mi (2,865.28 km) |
| South Portland to Coatesville (Pennsylvania) | 380.09 mi (611.70 km) |
| South Portland to Cockeysville (Maryland) | 435.30 mi (700.54 km) |
| South Portland to Cocoa (Florida) | 1,203.11 mi (1,936.22 km) |
| South Portland to Cocoa Beach (Florida) | 1,202.45 mi (1,935.16 km) |
| South Portland to Coconut Creek (Florida) | 1,320.95 mi (2,125.87 km) |
| South Portland to Coeur d'Alene (Idaho) | 2,228.83 mi (3,586.96 km) |
| South Portland to Cohoes (New York) | 182.06 mi (292.99 km) |
