There are
1,413 mi
from Rapid City, SD to San Mateo, CA
That's the driving distance. It would take 1 day to go from Rapid City, South Dakota to San Mateo, California.
The flight distance (direct flight from Rapid City, SD to San Mateo, CA) is 1,091.86 mi.
1,413 mi = 2,274.48 kms