| Duncan to Salisbury (New York) | 1,394.71 mi (2,244.57 km) |
| Duncan to Salisbury (North Carolina) | 987.07 mi (1,588.54 km) |
| Duncan to Salmon Creek (Washington) | 1,508.65 mi (2,427.94 km) |
| Duncan to Salt Lake City (Utah) | 877.61 mi (1,412.38 km) |
| Duncan to Sammamish (Washington) | 1,536.32 mi (2,472.46 km) |
| Duncan to San Angelo (Texas) | 259.41 mi (417.48 km) |
| Duncan to San Anselmo (California) | 1,389.41 mi (2,236.04 km) |
| Duncan to San Antonio (Texas) | 352.60 mi (567.45 km) |
| Duncan to San Benito (Texas) | 581.38 mi (935.64 km) |
| Duncan to San Bernardino (California) | 1,103.87 mi (1,776.50 km) |
| Duncan to San Bruno (California) | 1,381.05 mi (2,222.58 km) |
| Duncan to San Buenaventura (California) | 1,212.65 mi (1,951.57 km) |
| Duncan to San Carlos (California) | 1,371.89 mi (2,207.84 km) |
| Duncan to San Carlos Park (Florida) | 1,106.60 mi (1,780.90 km) |
| Duncan to San Clemente (California) | 1,128.58 mi (1,816.27 km) |
