Purgatoire River track site, Paleontological site in La Junta, Colorado, US

Purgatoire River track site lies on Comanche National Grassland along the Purgatoire River south of La Junta, Otero County, Colorado. Its more than 100 trackways hold over 1500 individual footprints of biped and quadruped dinosaurs, set in limestone of the Jurassic Morrison Formation. The rock surface is cracked into irregular plates, with hollowed basins and elongated grooves running in loose lines.

The footprints were made roughly 150 million years ago when dinosaurs like Allosaurus, Apatosaurus, Diplodocus, and Stegosaurus lived near an ancient lakeshore. This site preserves a rare window into a past world where different species lived side by side in the same landscape.

The river's name comes from Spanish and was transformed by European settlers through French into "Picketwire," reflecting the mixed cultural past of the region. Locals and visitors today often use both names when describing the history of this landscape.

Reaching this site requires a hike of about 11 miles round trip through grassland terrain within the national grassland. Plan for a full day trip and bring plenty of water and sun protection, as shade is limited along the trail.

Scientists uncovered roughly 90 additional footprints in 2014 showing that massive plant-eating dinosaurs traveled in mixed herds. These findings suggest young and adult animals moved together, changing how we understand the behavior of these species.