The most famous discovery is the Purgatoire River dinosaur tracksite in Picket Wire Canyonlands. This tracksite contains compelling evidence that sauropod dinosaurs lived in herds while meat- eaters were solitary.
Over 1,800 prints in 130 separate trackways extend across a quarter mile expanse of bedrock where they were preserved—frozen in time—for 150 million years.
Skeletons of many famous dinosaurs such as Apatosaurus, Allosaurus, Camarasaurus, and Diplodocus have been excavated from the canyon walls surrounding the trackway.
Today the Purgatoire River is a deeply carved, rugged, and arid landscape, but imagine it as a deep and lush conifer forest, or a tropical sea. The fossils and landforms of this area are as distinctive a part of the landscape today as the vanished plants, animals, and ecosystems they represent.