There are
1,818 mi
from Longmont, CO to Lindenhurst, NY
That's the driving distance. It would take 1 day 9 hours to go from Longmont, Colorado to Lindenhurst, New York.
The flight distance (direct flight from Longmont, CO to Lindenhurst, NY) is 1,660.05 mi.
1,818 mi = 1.61 kms