There are
3,090 mi
from Somerville, MA to Walnut Creek, CA
That's the driving distance. It would take 2 days 6 hours to go from Somerville, Massachusetts to Walnut Creek, California.
The flight distance (direct flight from Somerville, MA to Walnut Creek, CA) is 2,669.07 mi.
3,090 mi = 4.83 kms