Hagerman Fossil Beds National Monument - Fossils

The fossils located within the Monument were deposited primarily in the Glenns Ferry Formation. This stratigraphy contains some of the most diverse and richest successions of Pliocene-aged (Blancan Land Mammal Age) fossils known to exist anywhere. The Beringian Land Bridge between North America and Asia and the Panamanian Isthmus between North and South America allowed dispersal of different species between these continents, making the faunal assemblage at Hagerman international.

The Monument is of significant scientific value and produces fossils of rare quality and exceptional quantities. The fossils are very well preserved in relatively undisturbed deposits, which allow us to learn a great deal about the ecological relationships of the area. There are in excess of 600 known individual fossil locations within the Monument, representing over 200 separate species of plants and animals. Of these, 44 are holotypes, meaning they were the first of their kind discovered. Over 100 species of vertebrates have currently been identified, including 18 fish, 4 amphibians, 9 reptiles, 27 birds, and 50 mammals, as well as freshwater snails and clams, and plant pollen.