The CU Museum of Natural History maintains an online archive of vertebrate observations. Deposited in this collection are images, audio recordings, field notes, and other documentation associated with non-vouchered vertebrate specimens. Taxonomic coverage includes observations for mammal, reptile and amphibian species, dating from 1950 to present. The geographic scope spans North America, with emphasis in Colorado, the southwest, and Mexico. Many reptiles cataloged in the UCM Observation collection represent range extensions and first county occurrence records. Also notable is a bat call library of over 200 recordings from Boulder County with accompanying field data.