Originally preserved in 1915 to protect its famous Dinosaur Quarry, the monument was greatly expanded in 1938 to include its wealth of natural history. The park's wild landscapes, topography, geology, paleontology, and history make it a unique resource for both science and recreation. The park contains over 800 paleontological sites and has fossils of dinosaurs including "Allosaurus", "Deinonychus", "Abydosaurus", and various sauropods. The "Abydosaurus" consists of a nearly complete skull, the lower jaw, and first four neck vertebrae. The specimen was found at the base of the Mussentuchit Member of the Cedar Mountain Formation and is the holotype for the description.