Ten species of Pleistocene mammals are represented in a collection of fossils from a placer mining site at Lost Chicken Creek. Among these are four extinct species, an extinct subspecies, two species now extinct in the region, and three species that still occupy the area. Bison crassicornis (large-horned bison), Equus (Asinus) lambei (Yukon wild ass), and Rangifer tarandus (caribou) remains are commonest. Equus (Asinus) cf. kiang (kiang-like wild ass) is recorded for the first time from Alaska.These mammals seem to have occupied a cool steppe-like grassland during late Wisconsin time. Bones of horse, wapiti, bison, and helmeted muskox (Symbos) have yielded radiocarbon dates between 27 000 and 10 000 years BP. The dated bison bone was modified by man, indicating that people were present, and probably hunting and butchering bison, in easternmost Alaska at the close of the Wisconsin glaciation.