There are
1,566 mi
from Great Falls, MT to Seagoville, TX
That's the driving distance. It would take 1 day 3 hours to go from Great Falls, Montana to Seagoville, Texas.
The flight distance (direct flight from Great Falls, MT to Seagoville, TX) is 1,285.08 mi.
1,566 mi = 2,519.44 kms