Miles between Boulder, CO and San Marcos, CA

There are
1,059 mi
from Boulder, CO to San Marcos, CA

That's the driving distance. It would take 18 hours 41 mins to go from Boulder, Colorado to San Marcos, California.

The flight distance (direct flight from Boulder, CO to San Marcos, CA) is 811.82 mi.

1,059 mi = 1.61 kms