| Difficult Run to Morristown (New Jersey) | 200.78 mi (323.12 km) |
| Difficult Run to Morristown (Tennessee) | 375.46 mi (604.25 km) |
| Difficult Run to Morrisville (North Carolina) | 226.96 mi (365.25 km) |
| Difficult Run to Morro Bay (California) | 2,385.91 mi (3,839.75 km) |
| Difficult Run to Morton (Illinois) | 653.97 mi (1,052.47 km) |
| Difficult Run to Morton Grove (Illinois) | 589.68 mi (948.99 km) |
| Difficult Run to Moscow (Idaho) | 2,057.42 mi (3,311.11 km) |
| Difficult Run to Moses Lake (Washington) | 2,164.96 mi (3,484.16 km) |
| Difficult Run to Moss Bluff (Louisiana) | 1,077.43 mi (1,733.95 km) |
| Difficult Run to Moss Point (Mississippi) | 862.95 mi (1,388.79 km) |
| Difficult Run to Moultrie (Georgia) | 646.31 mi (1,040.14 km) |
| Difficult Run to Mounds View (Minnesota) | 918.06 mi (1,477.47 km) |
| Difficult Run to Mount Airy (North Carolina) | 243.41 mi (391.73 km) |
| Difficult Run to Mount Clemens (Michigan) | 386.05 mi (621.28 km) |
| Difficult Run to Mount Dora (Florida) | 738.85 mi (1,189.07 km) |
