There are
2,041 mi
from Dekalb, IL to Vallejo, CA
That's the driving distance. It would take 1 day 10 hours to go from Dekalb, Illinois to Vallejo, California.
The flight distance (direct flight from Dekalb, IL to Vallejo, CA) is 1,781.07 mi.
2,041 mi = 3,284.53 kms