| Difficult Run to Monticello (Minnesota) | 949.75 mi (1,528.47 km) |
| Difficult Run to Montrose (Colorado) | 1,638.16 mi (2,636.36 km) |
| Difficult Run to Moody (Alabama) | 627.26 mi (1,009.48 km) |
| Difficult Run to Moore (Oklahoma) | 1,133.63 mi (1,824.40 km) |
| Difficult Run to Moorestown-Lenola (New Jersey) | 146.88 mi (236.38 km) |
| Difficult Run to Mooresville (North Carolina) | 298.53 mi (480.43 km) |
| Difficult Run to Moorhead (Minnesota) | 1,121.42 mi (1,804.75 km) |
| Difficult Run to Moorpark (California) | 2,305.79 mi (3,710.81 km) |
| Difficult Run to Moraga (California) | 2,401.80 mi (3,865.32 km) |
| Difficult Run to Moreno Valley (California) | 2,224.88 mi (3,580.59 km) |
| Difficult Run to Morgan City (Louisiana) | 1,011.97 mi (1,628.61 km) |
| Difficult Run to Morgan Hill (California) | 2,390.40 mi (3,846.98 km) |
| Difficult Run to Morganton (North Carolina) | 323.81 mi (521.13 km) |
| Difficult Run to Morgantown (West Virginia) | 148.05 mi (238.27 km) |
| Difficult Run to Morris (Illinois) | 609.36 mi (980.68 km) |
