There are
790 mi
from Thornton, CO to Fayetteville, AR
That's the driving distance. It would take 14 hours 8 mins to go from Thornton, Colorado to Fayetteville, Arkansas.
The flight distance (direct flight from Thornton, CO to Fayetteville, AR) is 644.52 mi.
790 mi = 1,271.38 kms