There are
1,633 mi
from San Marcos, CA to Sioux City, IA
That's the driving distance. It would take 1 day 4 hours to go from San Marcos, California to Sioux City, Iowa.
The flight distance (direct flight from San Marcos, CA to Sioux City, IA) is 1,299.65 mi.
1,633 mi = 1.61 kms