There are
1,360 mi
from Wilmington, DE to Watertown, SD
That's the driving distance. It would take 1 day 2 hours to go from Wilmington, Delaware to Watertown, South Dakota.
The flight distance (direct flight from Wilmington, DE to Watertown, SD) is 1,153.87 mi.
1,360 mi = 1.61 kms