| Duncan to Mitchell (South Dakota) | 634.90 mi (1,021.77 km) |
| Duncan to Mitchellville (Maryland) | 1,204.44 mi (1,938.36 km) |
| Duncan to Moberly (Missouri) | 452.81 mi (728.73 km) |
| Duncan to Mobile (Alabama) | 629.60 mi (1,013.25 km) |
| Duncan to Modesto (California) | 1,302.96 mi (2,096.90 km) |
| Duncan to Mokena (Illinois) | 728.53 mi (1,172.45 km) |
| Duncan to Moline (Illinois) | 626.85 mi (1,008.81 km) |
| Duncan to Moncks Corner (South Carolina) | 1,030.65 mi (1,658.67 km) |
| Duncan to Monfort Heights (Ohio) | 801.80 mi (1,290.37 km) |
| Duncan to Monmouth (Oregon) | 1,513.41 mi (2,435.60 km) |
| Duncan to Monroe (Georgia) | 813.01 mi (1,308.42 km) |
| Duncan to Monroe (Louisiana) | 364.37 mi (586.39 km) |
| Duncan to Monroe (Michigan) | 937.23 mi (1,508.33 km) |
| Duncan to Monroe (North Carolina) | 984.64 mi (1,584.63 km) |
| Duncan to Monroe (Ohio) | 820.08 mi (1,319.80 km) |
