There are
1,216 mi
from Thornton, CO to Lathrop, CA
That's the driving distance. It would take 20 hours 44 mins to go from Thornton, Colorado to Lathrop, California.
The flight distance (direct flight from Thornton, CO to Lathrop, CA) is 887.43 mi.
1,216 mi = 1.61 kms