This study illuminates structural variability in hunter/gatherer diet and subsistence behavior under conditions of low population density and rapid ecological reorganization. More specifically, it explores several unresolved issues relating to the diet and subsistence behavior of post-Clovis Paleoindian hunter/gatherers who inhabited the Northwestern Great Plains of North America during the late Pleistocene/early Holocene (ca. 11-8,000 years ago).This study analyses faunal assemblages from the Agate Basin and Clary Ranch sites in the Great plains, reinterpreting existing ideas about diet and subsistence patterns during the Ice Age.