There are
2,069 mi
from Walnut Creek, CA to Decatur, IL
That's the driving distance. It would take 1 day 11 hours to go from Walnut Creek, California to Decatur, Illinois.
The flight distance (direct flight from Walnut Creek, CA to Decatur, IL) is 1,775.89 mi.
2,069 mi = 3,330.30 kms