| Duncan to Conyers (Georgia) | 798.33 mi (1,284.78 km) |
| Duncan to Cookeville (Tennessee) | 707.70 mi (1,138.93 km) |
| Duncan to Coolidge (Arizona) | 788.84 mi (1,269.51 km) |
| Duncan to Coon Rapids (Minnesota) | 774.08 mi (1,245.77 km) |
| Duncan to Cooper City (Florida) | 1,202.09 mi (1,934.58 km) |
| Duncan to Coos Bay (Oregon) | 1,531.47 mi (2,464.67 km) |
| Duncan to Copiague (New York) | 1,402.51 mi (2,257.12 km) |
| Duncan to Coppell (Texas) | 121.38 mi (195.34 km) |
| Duncan to Copperas Cove (Texas) | 236.41 mi (380.47 km) |
| Duncan to Coral Gables (Florida) | 1,216.05 mi (1,957.04 km) |
| Duncan to Coral Springs (Florida) | 1,195.05 mi (1,923.25 km) |
| Duncan to Coral Terrace (Florida) | 1,212.67 mi (1,951.60 km) |
| Duncan to Coralville (Iowa) | 601.94 mi (968.72 km) |
| Duncan to Coram (New York) | 1,424.89 mi (2,293.14 km) |
| Duncan to Corcoran (California) | 1,222.20 mi (1,966.93 km) |
