There are
1,165 mi
from Billings, MT to Larkspur, CA
That's the driving distance. It would take 21 hours 5 mins to go from Billings, Montana to Larkspur, California.
The flight distance (direct flight from Billings, MT to Larkspur, CA) is 900.96 mi.
1,165 mi = 1.61 kms