There are
1,967 mi
from Port Arthur, TX to Missoula, MT
That's the driving distance. It would take 1 day 10 hours to go from Port Arthur, Texas to Missoula, Montana.
The flight distance (direct flight from Port Arthur, TX to Missoula, MT) is 1,590.29 mi.
1,967 mi = 3,166.10 kms