There are
1,555 mi
from San Marcos, CA to Joplin, MO
That's the driving distance. It would take 1 day 3 hours to go from San Marcos, California to Joplin, Missouri.
The flight distance (direct flight from San Marcos, CA to Joplin, MO) is 1,305.60 mi.
1,555 mi = 2,502.35 kms