There are
1,427 mi
from Great Falls, MT to Kankakee, IL
That's the driving distance. It would take 1 day 1 hour to go from Great Falls, Montana to Kankakee, Illinois.
The flight distance (direct flight from Great Falls, MT to Kankakee, IL) is 1,234.02 mi.
1,427 mi = 2,297.12 kms