There are
2,054 mi
from St Peters, MO to Ukiah, CA
That's the driving distance. It would take 1 day 12 hours to go from St Peters, Missouri to Ukiah, California.
The flight distance (direct flight from St Peters, MO to Ukiah, CA) is 1,742.17 mi.
2,054 mi = 3,305.34 kms