| Difficult Run to Superior (Colorado) | 1,480.21 mi (2,382.17 km) |
| Difficult Run to Superior (Wisconsin) | 918.40 mi (1,478.02 km) |
| Difficult Run to Surprise (Arizona) | 1,975.43 mi (3,179.15 km) |
| Difficult Run to Susanville (California) | 2,280.57 mi (3,670.22 km) |
| Difficult Run to Sussex (Wisconsin) | 637.24 mi (1,025.54 km) |
| Difficult Run to Suwanee (Georgia) | 501.51 mi (807.09 km) |
| Difficult Run to Swansea (Illinois) | 681.15 mi (1,096.20 km) |
| Difficult Run to Sweetwater (Florida) | 923.63 mi (1,486.44 km) |
| Difficult Run to Sweetwater (Texas) | 1,363.94 mi (2,195.05 km) |
| Difficult Run to Sycamore (Illinois) | 632.56 mi (1,018.01 km) |
| Difficult Run to Sylacauga (Alabama) | 635.35 mi (1,022.50 km) |
| Difficult Run to Sylvania (Ohio) | 387.18 mi (623.10 km) |
| Difficult Run to Syosset (New York) | 243.03 mi (391.11 km) |
| Difficult Run to Syracuse (New York) | 292.78 mi (471.19 km) |
| Difficult Run to Syracuse (Utah) | 1,832.02 mi (2,948.35 km) |
