The Illinois Natural History Survey Mammal Collection contains over 30,000 lots of specimens, from over 39,000 individuals, with over 58,000 preparations. Specimens are from over 170 species from 35 families, and preparations include skins, skulls, skeletons, frozen tissue, hair, fluid, and photos. These specimens are primarily used for research and as comparative material to identify specimens brought to the Survey. Most of the specimens are from Illinois and surrounding Midwestern states.