There are
625 mi
from Kennewick, WA to Eureka, CA
That's the driving distance. It would take 12 hours 40 mins to go from Kennewick, Washington to Eureka, California.
The flight distance (direct flight from Kennewick, WA to Eureka, CA) is 450.49 mi.
625 mi = 1,006.50 kms