There are
1,667 mi
from Great Falls, MT to Sandusky, OH
That's the driving distance. It would take 1 day 5 hours to go from Great Falls, Montana to Sandusky, Ohio.
The flight distance (direct flight from Great Falls, MT to Sandusky, OH) is 1,460.98 mi.
1,667 mi = 2,682.40 kms