There are
2,035 mi
from Simi Valley, CA to Mt Prospect, IL
That's the driving distance. It would take 1 day 12 hours to go from Simi Valley, California to Mt Prospect, Illinois.
The flight distance (direct flight from Simi Valley, CA to Mt Prospect, IL) is 1,748.94 mi.
2,035 mi = 3.22 kms