Natural history collections are a library of biological specimens and their associated data that are used to better understand the world. Traditionally they include preserved material that records, over time and geography, the historical basis for species and ecological diversity. Modern collections may include living specimens, images, videos and recordings; increasingly they include repositories of tissues and extracted DNA. Natural history collections provide basic infrastructure to scientists for research in global biodiversity, evolution, speciation, conservation biology, paleogeography, monitoring ecological disturbance, climate change, invasive species, and addressing emerging diseases (agricultural, human, veterinary). Collections are crucial tools for instruction for the university and K-12; they often include displays and events that are vehicles of outreach and interchange with local communities. The University of California Riverside has a range of natural history collections approaching 4 million specimens. The collections are worldwide in scope and they particularly reflect Southwestern North America and historical strength of the campus in agriculture, ecology and conservation biology.