There are
1,866 mi
from Simi Valley, CA to Alton, IL
That's the driving distance. It would take 1 day 9 hours to go from Simi Valley, California to Alton, Illinois.
The flight distance (direct flight from Simi Valley, CA to Alton, IL) is 1,611.51 mi.
1,866 mi = 1.61 kms