| Duncan to Romeoville (Illinois) | 723.90 mi (1,165.01 km) |
| Duncan to Romulus (Michigan) | 948.31 mi (1,526.16 km) |
| Duncan to Ronkonkoma (New York) | 1,417.87 mi (2,281.84 km) |
| Duncan to Roosevelt (New York) | 1,392.72 mi (2,241.37 km) |
| Duncan to Rosamond (California) | 1,150.99 mi (1,852.35 km) |
| Duncan to Rosaryville (Maryland) | 1,202.22 mi (1,934.79 km) |
| Duncan to Roscoe (Illinois) | 726.59 mi (1,169.34 km) |
| Duncan to Rose Hill (Virginia) | 1,187.36 mi (1,910.87 km) |
| Duncan to Roseburg (Oregon) | 1,485.90 mi (2,391.32 km) |
| Duncan to Rosedale (California) | 1,204.27 mi (1,938.08 km) |
| Duncan to Rosedale (Maryland) | 1,224.66 mi (1,970.90 km) |
| Duncan to Roselle (Illinois) | 739.97 mi (1,190.87 km) |
| Duncan to Roselle (New Jersey) | 1,357.52 mi (2,184.71 km) |
| Duncan to Roselle Park (New Jersey) | 1,357.33 mi (2,184.41 km) |
| Duncan to Rosemead (California) | 1,149.22 mi (1,849.50 km) |
