There are
1,838 mi
from San Marcos, CA to Bridgeton, MO
That's the driving distance. It would take 1 day 8 hours to go from San Marcos, California to Bridgeton, Missouri.
The flight distance (direct flight from San Marcos, CA to Bridgeton, MO) is 1,539.88 mi.
1,838 mi = 2,957.31 kms