| Duncan to Robertsville (New Jersey) | 1,351.96 mi (2,175.77 km) |
| Duncan to Robinson (Texas) | 218.54 mi (351.70 km) |
| Duncan to Robstown (Texas) | 466.40 mi (750.59 km) |
| Duncan to Rochester (Michigan) | 975.10 mi (1,569.27 km) |
| Duncan to Rochester (Minnesota) | 716.03 mi (1,152.34 km) |
| Duncan to Rochester (New Hampshire) | 1,560.89 mi (2,512.01 km) |
| Duncan to Rochester (New York) | 1,239.90 mi (1,995.43 km) |
| Duncan to Rochester Hills (Michigan) | 972.72 mi (1,565.45 km) |
| Duncan to Rock Hill (South Carolina) | 958.63 mi (1,542.77 km) |
| Duncan to Rock Island (Illinois) | 623.06 mi (1,002.72 km) |
| Duncan to Rock Springs (Wyoming) | 783.26 mi (1,260.54 km) |
| Duncan to Rockford (Illinois) | 716.43 mi (1,152.99 km) |
| Duncan to Rockledge (Florida) | 1,098.64 mi (1,768.09 km) |
| Duncan to Rocklin (California) | 1,321.98 mi (2,127.53 km) |
| Duncan to Rockport (Texas) | 452.70 mi (728.55 km) |
