There are
1,959 mi
from Missoula, MT to Port Lavaca, TX
That's the driving distance. It would take 1 day 10 hours to go from Missoula, Montana to Port Lavaca, Texas.
The flight distance (direct flight from Missoula, MT to Port Lavaca, TX) is 1,571.11 mi.
1,959 mi = 1.61 kms