The Department of Earth Sciences contains six major collections. In geology: rocks, minerals, and meteorites. In paleontology: fossil vertebrates, invertebrates, and plants

The vertebrate paleontology collection consists mainly of Jurassic and Cretaceous dinosaurs, Cretaceous Seaway fishes and reptiles, and Cenozoic mammals from the American West. It also has a major focus in the vertebrates from the Late Cretaceous of Madagascar. The paleobotany collection is dominated by Cretaceous-Eocene leaves and is the second largest of its kind in the nation. The invertebrate paleontology collection’s main strengths are Cambrian-Ordovician trilobites, Cretaceous Seaway mollusks, and Eocene insects. The mineral collection focuses on Colorado and includes one of the nation’s most diverse collections of micromount minerals. The rock collection includes historical and building-stone collections, as well as representative rock units from the Rockies. The meteorite collection is one of the nation’s oldest, featuring historic samples from around the world with a significant fraction from Colorado.