Abstract
Mammoths were endemic on the North American continent during the late Pleistocene to early Holocene and are considered a keystone species in paleoecology. Here, I examined the skeletal remains of a mammoth excavated from southeastern Idaho to provide insight into its depositional age, taxonomy, and ontogeny. This multidisciplinary analysis revealed possibly the first M. jeffersonii hybrid reported in Idaho that lived 11,700 +/- 40 years ago. The remains belonged to a male mammoth that was a juvenile between 18 and 28 years old. Its remains were preserved in an ancient hot spring deposit during a time within 500-1000 years of the final megafaunal extinction on the continental landmasses. This mammoth is one of the last mammoths in mainland North America before the species’ ultimate extinction.