| Castle Rock to Reidsville (North Carolina) | 1,385.02 mi (2,228.98 km) |
| Castle Rock to Reisterstown (Maryland) | 1,490.62 mi (2,398.92 km) |
| Castle Rock to Rendon (Texas) | 633.56 mi (1,019.61 km) |
| Castle Rock to Reno (Nevada) | 799.02 mi (1,285.90 km) |
| Castle Rock to Renton (Washington) | 1,030.97 mi (1,659.19 km) |
| Castle Rock to Republic (Missouri) | 637.37 mi (1,025.75 km) |
| Castle Rock to Reston (Virginia) | 1,468.19 mi (2,362.82 km) |
| Castle Rock to Revere (Massachusetts) | 1,768.47 mi (2,846.08 km) |
| Castle Rock to Rexburg (Idaho) | 471.82 mi (759.31 km) |
| Castle Rock to Reynoldsburg (Ohio) | 1,170.93 mi (1,884.42 km) |
| Castle Rock to Rialto (California) | 782.36 mi (1,259.09 km) |
| Castle Rock to Richardson (Texas) | 633.62 mi (1,019.71 km) |
| Castle Rock to Richfield (Minnesota) | 703.21 mi (1,131.70 km) |
| Castle Rock to Richfield (Wisconsin) | 900.75 mi (1,449.62 km) |
| Castle Rock to Richland (Washington) | 871.47 mi (1,402.50 km) |
