Miles between Longmont, CO and Johnston, IA

There are
670 mi
from Longmont, CO to Johnston, IA

That's the driving distance. It would take 11 hours 48 mins to go from Longmont, Colorado to Johnston, Iowa.

The flight distance (direct flight from Longmont, CO to Johnston, IA) is 603.53 mi.

670 mi = 1,077.79 kms