There are
2,116 mi
from Walnut Creek, CA to Mt Prospect, IL
That's the driving distance. It would take 1 day 12 hours to go from Walnut Creek, California to Mt Prospect, Illinois.
The flight distance (direct flight from Walnut Creek, CA to Mt Prospect, IL) is 1,817.08 mi.
2,116 mi = 3,405.36 kms