| Duncan to Candler-McAfee (Georgia) | 782.03 mi (1,258.56 km) |
| Duncan to Caño Martin Peña (Puerto Rico) | 2,249.02 mi (3,619.45 km) |
| Duncan to Cañon City (Colorado) | 486.64 mi (783.17 km) |
| Duncan to Canóvanas (Puerto Rico) | 2,259.47 mi (3,636.26 km) |
| Duncan to Canton (Georgia) | 765.51 mi (1,231.97 km) |
| Duncan to Canton (Illinois) | 599.09 mi (964.14 km) |
| Duncan to Canton (Mississippi) | 473.49 mi (762.01 km) |
| Duncan to Canton (Ohio) | 1,001.31 mi (1,611.45 km) |
| Duncan to Canyon (Texas) | 229.00 mi (368.54 km) |
| Duncan to Canyon Lake (California) | 1,106.23 mi (1,780.31 km) |
| Duncan to Canyon Lake (Texas) | 322.91 mi (519.67 km) |
| Duncan to Cape Coral (Florida) | 1,091.08 mi (1,755.92 km) |
| Duncan to Cape Girardeau (Missouri) | 505.24 mi (813.10 km) |
| Duncan to Carbondale (Illinois) | 532.53 mi (857.03 km) |
| Duncan to Carlisle (Pennsylvania) | 1,199.58 mi (1,930.53 km) |
