There are
1,360 mi
from San Marcos, CA to Southlake, TX
That's the driving distance. It would take 23 hours 31 mins to go from San Marcos, California to Southlake, Texas.
The flight distance (direct flight from San Marcos, CA to Southlake, TX) is 1,158.53 mi.
1,360 mi = 1.61 kms