There are
1,785 mi
from Ventura, CA to Watertown, SD
That's the driving distance. It would take 1 day 7 hours to go from Ventura, California to Watertown, South Dakota.
The flight distance (direct flight from Ventura, CA to Watertown, SD) is 1,380.67 mi.
1,785 mi = 1.61 kms