Miles between San Marcos, CA and Alton, IL

There are
1,868 mi
from San Marcos, CA to Alton, IL

That's the driving distance. It would take 1 day 8 hours to go from San Marcos, California to Alton, Illinois.

The flight distance (direct flight from San Marcos, CA to Alton, IL) is 1,552.99 mi.

1,868 mi = 1.61 kms