There are
3,098 mi
from Somerville, MA to Petaluma, CA
That's the driving distance. It would take 2 days 7 hours to go from Somerville, Massachusetts to Petaluma, California.
The flight distance (direct flight from Somerville, MA to Petaluma, CA) is 2,688.85 mi.
3,098 mi = 4.83 kms