There are
2,058 mi
from San Marcos, CA to Shelbyville, TN
That's the driving distance. It would take 1 day 12 hours to go from San Marcos, California to Shelbyville, Tennessee.
The flight distance (direct flight from San Marcos, CA to Shelbyville, TN) is 1,752.73 mi.
2,058 mi = 3.22 kms