There are
1,560 mi
from Walnut Creek, CA to Mandan, ND
That's the driving distance. It would take 1 day 3 hours to go from Walnut Creek, California to Mandan, North Dakota.
The flight distance (direct flight from Walnut Creek, CA to Mandan, ND) is 1,238.57 mi.
1,560 mi = 2,511.04 kms