There are
1,947 mi
from St Charles, IL to Montclair, CA
That's the driving distance. It would take 1 day 10 hours to go from St Charles, Illinois to Montclair, California.
The flight distance (direct flight from St Charles, IL to Montclair, CA) is 1,679.10 mi.
1,947 mi = 3,132.68 kms