There are
2,909 mi
from Walnut Creek, CA to Mamaroneck, NY
That's the driving distance. It would take 2 days 3 hours to go from Walnut Creek, California to Mamaroneck, New York.
The flight distance (direct flight from Walnut Creek, CA to Mamaroneck, NY) is 2,555.14 mi.
2,909 mi = 4,681.51 kms