There are
874 mi
from Thornton, CO to Platteville, WI
That's the driving distance. It would take 15 hours 40 mins to go from Thornton, Colorado to Platteville, Wisconsin.
The flight distance (direct flight from Thornton, CO to Platteville, WI) is 776.84 mi.
874 mi = 1,407.01 kms