Between 1912 to 1916, Gidley excavated the Cumberland Bone Cave, where 41 genera of mammals were found, about 16 per cent of which are extinct. Numerous excellent skulls and enough bones to reconstruct skeletons for a number of the species were present. Skeletons of the Pleistocenecave bear and an extinct saber-toothed cat from the Bone Cave are on permanent exhibit in the Ice Age Mammal exhibit at the National Museum of Natural History, Smithsonian Institution in Washington, DC. Many of the fossilized bones date from 200,000 years ago. The Cumberland Bone cave represents one of the finest Pleistocene-era faunas known from eastern North America.