There are
2,019 mi
from St Charles, MO to Walnut Creek, CA
That's the driving distance. It would take 1 day 10 hours to go from St Charles, Missouri to Walnut Creek, California.
The flight distance (direct flight from St Charles, MO to Walnut Creek, CA) is 1,702.36 mi.
2,019 mi = 3,249.03 kms