Miles between San Marcos, CA and Thornton, CO

There are
1,054 mi
from San Marcos, CA to Thornton, CO

That's the driving distance. It would take 18 hours 31 mins to go from San Marcos, California to Thornton, Colorado.

The flight distance (direct flight from San Marcos, CA to Thornton, CO) is 820.06 mi.

1,054 mi = 1.61 kms