There are
2,006 mi
from St Charles, MO to Vallejo, CA
That's the driving distance. It would take 1 day 10 hours to go from St Charles, Missouri to Vallejo, California.
The flight distance (direct flight from St Charles, MO to Vallejo, CA) is 1,709.82 mi.
2,006 mi = 3,228.16 kms