There are
1,740 mi
from St Charles, MO to Rancho Mirage, CA
That's the driving distance. It would take 1 day 6 hours to go from St Charles, Missouri to Rancho Mirage, California.
The flight distance (direct flight from St Charles, MO to Rancho Mirage, CA) is 1,479.10 mi.
1,740 mi = 2,799.75 kms