There are
2,120 mi
from San Marcos, CA to Lyndon, KY
That's the driving distance. It would take 1 day 13 hours to go from San Marcos, California to Lyndon, Kentucky.
The flight distance (direct flight from San Marcos, CA to Lyndon, KY) is 1,796.86 mi.
2,120 mi = 3.22 kms