Note that at times this location may require a higher clearance vehicle.  8.2 miles North of Arches National Park entrance is Willow Springs Road on the right side of HWY 191.  It is the entrance to Utah Raptor State Park.   3.1 miles down the dirt road are the dinosaur tracks.  The location is indicated by a large sign.  Here is a link with directions Willow Creek Dino Tracks Directions (Google Maps)

10.8 miles North of the Arches National Park entrance on the left side of 191 you will see Mill Creek road.  It is an easy dirt road for about 1 mile to the track site on the right side.  This location has one of the largest track sites in North America with over 200 tracks here.  Mill Creek Dino Tracks Directions  (Google Maps)