There are
2,555 mi
from Missoula, MT to Watertown, MA
That's the driving distance. It would take 1 day 21 hours to go from Missoula, Montana to Watertown, Massachusetts.
The flight distance (direct flight from Missoula, MT to Watertown, MA) is 2,102.92 mi.
2,555 mi = 3.22 kms