There are
1,724 mi
from Irvine, CA to Watertown, SD
That's the driving distance. It would take 1 day 6 hours to go from Irvine, California to Watertown, South Dakota.
The flight distance (direct flight from Irvine, CA to Watertown, SD) is 1,343.96 mi.
1,724 mi = 1.61 kms