There are
977 mi
from Longmont, CO to Cape Girardeau, MO
That's the driving distance. It would take 17 hours 18 mins to go from Longmont, Colorado to Cape Girardeau, Missouri.
The flight distance (direct flight from Longmont, CO to Cape Girardeau, MO) is 861.60 mi.
977 mi = 1,573.05 kms