There are
755 mi
from Missoula, MT to Mandan, ND
That's the driving distance. It would take 12 hours 26 mins to go from Missoula, Montana to Mandan, North Dakota.
The flight distance (direct flight from Missoula, MT to Mandan, ND) is 619.79 mi.
755 mi = 1,215.55 kms