| Duncan to Monticello (Minnesota) | 774.47 mi (1,246.38 km) |
| Duncan to Montrose (Colorado) | 614.55 mi (989.03 km) |
| Duncan to Moody (Alabama) | 656.78 mi (1,056.99 km) |
| Duncan to Moore (Oklahoma) | 60.05 mi (96.64 km) |
| Duncan to Moorestown-Lenola (New Jersey) | 1,312.78 mi (2,112.72 km) |
| Duncan to Mooresville (North Carolina) | 968.26 mi (1,558.26 km) |
| Duncan to Moorhead (Minnesota) | 853.87 mi (1,374.18 km) |
| Duncan to Moorpark (California) | 1,192.45 mi (1,919.06 km) |
| Duncan to Moraga (California) | 1,364.67 mi (2,196.22 km) |
| Duncan to Moreno Valley (California) | 1,100.67 mi (1,771.36 km) |
| Duncan to Morgan City (Louisiana) | 516.23 mi (830.79 km) |
| Duncan to Morgan Hill (California) | 1,337.12 mi (2,151.89 km) |
| Duncan to Morganton (North Carolina) | 919.20 mi (1,479.30 km) |
| Duncan to Morgantown (West Virginia) | 1,049.21 mi (1,688.54 km) |
| Duncan to Morris (Illinois) | 699.41 mi (1,125.60 km) |
