There are
1,261 mi
from Great Falls, MT to Temecula, CA
That's the driving distance. It would take 21 hours 13 mins to go from Great Falls, Montana to Temecula, California.
The flight distance (direct flight from Great Falls, MT to Temecula, CA) is 1,014.60 mi.
1,261 mi = 2,029.01 kms