| Difficult Run to Foothill Farms (California) | 2,345.90 mi (3,775.37 km) |
| Difficult Run to Fords (New Jersey) | 196.85 mi (316.80 km) |
| Difficult Run to Forest (Virginia) | 149.08 mi (239.92 km) |
| Difficult Run to Forest Acres (South Carolina) | 392.02 mi (630.90 km) |
| Difficult Run to Forest City (Florida) | 745.36 mi (1,199.54 km) |
| Difficult Run to Forest Grove (Oregon) | 2,353.20 mi (3,787.12 km) |
| Difficult Run to Forest Hill (Texas) | 1,193.72 mi (1,921.11 km) |
| Difficult Run to Forest Hills (Michigan) | 508.75 mi (818.75 km) |
| Difficult Run to Forest Lake (Minnesota) | 910.78 mi (1,465.76 km) |
| Difficult Run to Forest Park (Georgia) | 534.21 mi (859.73 km) |
| Difficult Run to Forest Park (Illinois) | 587.36 mi (945.27 km) |
| Difficult Run to Forest Park (Ohio) | 385.77 mi (620.83 km) |
| Difficult Run to Forestville (Maryland) | 25.85 mi (41.60 km) |
| Difficult Run to Forestville (Ohio) | 375.59 mi (604.46 km) |
| Difficult Run to Forney (Texas) | 1,149.00 mi (1,849.13 km) |
