| Difficult Run to Mill Creek East (Washington) | 2,300.22 mi (3,701.84 km) |
| Difficult Run to Mill Valley (California) | 2,422.56 mi (3,898.74 km) |
| Difficult Run to Millbrae (California) | 2,421.19 mi (3,896.53 km) |
| Difficult Run to Millbrook (Alabama) | 671.65 mi (1,080.92 km) |
| Difficult Run to Millcreek (Utah) | 1,822.96 mi (2,933.77 km) |
| Difficult Run to Milledgeville (Georgia) | 519.30 mi (835.74 km) |
| Difficult Run to Miller Place (New York) | 270.47 mi (435.28 km) |
| Difficult Run to Millington (Tennessee) | 733.38 mi (1,180.26 km) |
| Difficult Run to Millville (New Jersey) | 127.32 mi (204.90 km) |
| Difficult Run to Milpitas (California) | 2,397.62 mi (3,858.59 km) |
| Difficult Run to Milton (Georgia) | 507.75 mi (817.15 km) |
| Difficult Run to Milwaukee (Wisconsin) | 623.50 mi (1,003.43 km) |
| Difficult Run to Milwaukie (Oregon) | 2,330.18 mi (3,750.07 km) |
| Difficult Run to Minden (Louisiana) | 991.09 mi (1,595.01 km) |
| Difficult Run to Mineola (New York) | 234.42 mi (377.26 km) |
