There are
2,133 mi
from Great Falls, MT to Lansdowne, PA
That's the driving distance. It would take 1 day 14 hours to go from Great Falls, Montana to Lansdowne, Pennsylvania.
The flight distance (direct flight from Great Falls, MT to Lansdowne, PA) is 1,854.91 mi.
2,133 mi = 3,432.74 kms