There are
2,857 mi
from Ukiah, CA to Hilton Head Island, SC
That's the driving distance. It would take 2 days 2 hours to go from Ukiah, California to Hilton Head Island, South Carolina.
The flight distance (direct flight from Ukiah, CA to Hilton Head Island, SC) is 2,407.85 mi.
2,857 mi = 4,598.59 kms