| Duncan to Roy (Utah) | 894.88 mi (1,440.17 km) |
| Duncan to Royal Kunia (Hawaii) | 3,724.58 mi (5,994.13 km) |
| Duncan to Royal Oak (Michigan) | 967.43 mi (1,556.92 km) |
| Duncan to Royal Palm Beach (Florida) | 1,180.93 mi (1,900.52 km) |
| Duncan to Royse City (Texas) | 142.04 mi (228.59 km) |
| Duncan to Ruskin (Florida) | 1,029.60 mi (1,656.98 km) |
| Duncan to Russellville (Alabama) | 580.01 mi (933.44 km) |
| Duncan to Russellville (Arkansas) | 275.71 mi (443.72 km) |
| Duncan to Ruston (Louisiana) | 334.45 mi (538.24 km) |
| Duncan to Rutherford (New Jersey) | 1,367.59 mi (2,200.93 km) |
| Duncan to Rutland (Vermont) | 1,469.74 mi (2,365.31 km) |
| Duncan to Sabana Grande (Puerto Rico) | 2,215.16 mi (3,564.95 km) |
| Duncan to Sachse (Texas) | 132.98 mi (214.01 km) |
| Duncan to Saco (Maine) | 1,589.99 mi (2,558.84 km) |
| Duncan to Sacramento (California) | 1,332.28 mi (2,144.09 km) |
