| Difficult Run to Southern Pines (North Carolina) | 280.22 mi (450.97 km) |
| Difficult Run to Southfield (Michigan) | 396.05 mi (637.38 km) |
| Difficult Run to Southgate (Michigan) | 382.83 mi (616.11 km) |
| Difficult Run to Southlake (Texas) | 1,178.70 mi (1,896.94 km) |
| Difficult Run to Spanaway (Washington) | 2,312.95 mi (3,722.33 km) |
| Difficult Run to Spanish Fork (Utah) | 1,818.72 mi (2,926.95 km) |
| Difficult Run to Spanish Lake (Missouri) | 691.54 mi (1,112.92 km) |
| Difficult Run to Spanish Springs (Nevada) | 2,242.83 mi (3,609.48 km) |
| Difficult Run to Sparks (Nevada) | 2,246.51 mi (3,615.40 km) |
| Difficult Run to Spartanburg (South Carolina) | 372.33 mi (599.20 km) |
| Difficult Run to Spearfish (South Dakota) | 1,412.09 mi (2,272.53 km) |
| Difficult Run to Speedway (Indiana) | 479.36 mi (771.45 km) |
| Difficult Run to Spencer (Iowa) | 971.21 mi (1,563.02 km) |
| Difficult Run to Spokane (Washington) | 2,079.31 mi (3,346.32 km) |
| Difficult Run to Spokane Valley (Washington) | 2,070.07 mi (3,331.46 km) |
