There are
1,740 mi
from San Mateo, CA to San Marcos, TX
That's the driving distance. It would take 1 day 6 hours to go from San Mateo, California to San Marcos, Texas.
The flight distance (direct flight from San Mateo, CA to San Marcos, TX) is 1,493.02 mi.
1,740 mi = 1.61 kms