There are
1,947 mi
from Great Falls, MT to San Benito, TX
That's the driving distance. It would take 1 day 10 hours to go from Great Falls, Montana to San Benito, Texas.
The flight distance (direct flight from Great Falls, MT to San Benito, TX) is 1,653.02 mi.
1,947 mi = 3,133.63 kms