| Castle Rock to Fortuna Foothills (Arizona) | 706.14 mi (1,136.43 km) |
| Castle Rock to Foster City (California) | 948.84 mi (1,527.01 km) |
| Castle Rock to Fostoria (Ohio) | 1,134.19 mi (1,825.30 km) |
| Castle Rock to Fountain (Colorado) | 48.39 mi (77.88 km) |
| Castle Rock to Fountain Hills (Arizona) | 552.09 mi (888.51 km) |
| Castle Rock to Fountain Inn (South Carolina) | 1,286.71 mi (2,070.75 km) |
| Castle Rock to Fountain Valley (California) | 824.57 mi (1,327.01 km) |
| Castle Rock to Fountainebleau (Florida) | 1,699.75 mi (2,735.48 km) |
| Castle Rock to Four Corners (Oregon) | 1,001.53 mi (1,611.81 km) |
| Castle Rock to Four Corners (Texas) | 849.62 mi (1,367.33 km) |
| Castle Rock to Four Square Mile (Colorado) | 21.12 mi (33.99 km) |
| Castle Rock to Fox Crossing (Wisconsin) | 905.60 mi (1,457.42 km) |
| Castle Rock to Fox Lake (Illinois) | 894.03 mi (1,438.80 km) |
| Castle Rock to Framingham (Massachusetts) | 1,747.07 mi (2,811.64 km) |
| Castle Rock to Franconia (Virginia) | 1,480.32 mi (2,382.35 km) |
