| Difficult Run to Friendswood (Texas) | 1,205.49 mi (1,940.04 km) |
| Difficult Run to Frisco (Texas) | 1,155.51 mi (1,859.61 km) |
| Difficult Run to Front Royal (Virginia) | 45.01 mi (72.44 km) |
| Difficult Run to Fruit Cove (Florida) | 654.90 mi (1,053.96 km) |
| Difficult Run to Fruita (Colorado) | 1,676.08 mi (2,697.38 km) |
| Difficult Run to Fruitville (Florida) | 851.95 mi (1,371.09 km) |
| Difficult Run to Fuller Heights (Florida) | 804.27 mi (1,294.35 km) |
| Difficult Run to Fullerton (California) | 2,264.67 mi (3,644.63 km) |
| Difficult Run to Fullerton (Pennsylvania) | 155.15 mi (249.68 km) |
| Difficult Run to Fulshear (Texas) | 1,230.86 mi (1,980.88 km) |
| Difficult Run to Fulton (Missouri) | 784.68 mi (1,262.82 km) |
| Difficult Run to Fulton (New York) | 308.90 mi (497.12 km) |
| Difficult Run to Fuquay-Varina (North Carolina) | 241.61 mi (388.83 km) |
| Difficult Run to Gadsden (Alabama) | 588.08 mi (946.43 km) |
| Difficult Run to Gaffney (South Carolina) | 355.52 mi (572.15 km) |
