There are
1,264 mi
from Great Falls, MT to Los Alamitos, CA
That's the driving distance. It would take 21 hours 17 mins to go from Great Falls, Montana to Los Alamitos, California.
The flight distance (direct flight from Great Falls, MT to Los Alamitos, CA) is 1,009.78 mi.
1,264 mi = 2,034.37 kms