Morrison Formation

The Morrison Formation is a sedimentary rock formation spanning multiple western US states, made of mudstone, sandstone, and siltstone in shades of light gray to red. These layers contain preserved remains of dinosaurs and other prehistoric creatures from the Jurassic period.

The formation took shape during the Jurassic period and first became known through fossil discoveries in Colorado in 1877. These findings sparked intensive scientific excavations that continue to this day.

The formation serves as a natural museum, preserving remains of prehistoric species including Allosaurus, Diplodocus, and Camarasaurus within its sedimentary layers.

You can visit multiple excavation sites across different states, with major access points at Dinosaur National Monument and the Cleveland-Lloyd Dinosaur Quarry in Utah. When visiting, wear comfortable hiking shoes and prepare for changing weather conditions in the highland regions.

The formation holds an unusual concentration of Allosaurus fossils, comprising roughly three quarters of all specimens found across North America. This remarkable abundance of this particular predatory dinosaur species makes the site especially valuable to paleontological research.

Made from material: mudstone

GPS coordinates: 40.44139,-109.30111

Latest update: December 6, 2025 21:20