There are
2,758 mi
from Walnut Creek, CA to Harrisburg, PA
That's the driving distance. It would take 2 days to go from Walnut Creek, California to Harrisburg, Pennsylvania.
The flight distance (direct flight from Walnut Creek, CA to Harrisburg, PA) is 2,402.13 mi.
2,758 mi = 4,439.25 kms