There are
2,555 mi
from Waltham, MA to Missoula, MT
That's the driving distance. It would take 1 day 21 hours to go from Waltham, Massachusetts to Missoula, Montana.
The flight distance (direct flight from Waltham, MA to Missoula, MT) is 2,100.29 mi.
2,555 mi = 4,112.02 kms