There are
1,834 mi
from Downey, CA to Cahokia, IL
That's the driving distance. It would take 1 day 8 hours to go from Downey, California to Cahokia, Illinois.
The flight distance (direct flight from Downey, CA to Cahokia, IL) is 1,582.95 mi.
1,834 mi = 1.61 kms