| Difficult Run to Somersworth (New Hampshire) | 451.04 mi (725.88 km) |
| Difficult Run to Somerton (Arizona) | 2,123.85 mi (3,418.00 km) |
| Difficult Run to Somerville (Massachusetts) | 406.42 mi (654.07 km) |
| Difficult Run to Somerville (New Jersey) | 185.57 mi (298.65 km) |
| Difficult Run to Sonoma (California) | 2,411.10 mi (3,880.29 km) |
| Difficult Run to Soquel (California) | 2,409.28 mi (3,877.35 km) |
| Difficult Run to South Bend (Indiana) | 507.52 mi (816.77 km) |
| Difficult Run to South Bradenton (Florida) | 846.02 mi (1,361.54 km) |
| Difficult Run to South Burlington (Vermont) | 439.13 mi (706.70 km) |
| Difficult Run to South Charleston (West Virginia) | 238.93 mi (384.52 km) |
| Difficult Run to South Daytona (Florida) | 704.36 mi (1,133.57 km) |
| Difficult Run to South El Monte (California) | 2,267.11 mi (3,648.56 km) |
| Difficult Run to South Elgin (Illinois) | 614.30 mi (988.62 km) |
| Difficult Run to South Euclid (Ohio) | 285.27 mi (459.09 km) |
| Difficult Run to South Farmingdale (New York) | 242.01 mi (389.47 km) |
