| Castle Rock to Silver Firs (Washington) | 1,041.40 mi (1,675.98 km) |
| Castle Rock to Silver Spring (Maryland) | 1,484.77 mi (2,389.51 km) |
| Castle Rock to Silver Springs Shores (Florida) | 1,478.63 mi (2,379.63 km) |
| Castle Rock to Silverdale (Washington) | 1,057.25 mi (1,701.48 km) |
| Castle Rock to Silverton (Oregon) | 993.96 mi (1,599.62 km) |
| Castle Rock to Simi Valley (California) | 844.54 mi (1,359.15 km) |
| Castle Rock to Simpsonville (South Carolina) | 1,282.98 mi (2,064.75 km) |
| Castle Rock to Sioux City (Iowa) | 491.22 mi (790.54 km) |
| Castle Rock to Sioux Falls (South Dakota) | 509.17 mi (819.43 km) |
| Castle Rock to Skokie (Illinois) | 913.35 mi (1,469.90 km) |
| Castle Rock to Sleepy Hollow (New York) | 1,629.83 mi (2,622.96 km) |
| Castle Rock to Slidell (Louisiana) | 1,058.13 mi (1,702.90 km) |
| Castle Rock to Smithfield (North Carolina) | 1,472.67 mi (2,370.04 km) |
| Castle Rock to Smithfield (Utah) | 403.13 mi (648.77 km) |
| Castle Rock to Smithville (Missouri) | 548.62 mi (882.92 km) |
