Projectile points across the Northern Rocky Mountain front: the Billy Big Spring Site (Blackfeet Reservation, Montana)

In the recent past, the Front Ranges of the Northern Rocky Mountains formed a permeable boundary that people repeatedly crossed for trade, subsistence, or warfare, and where people occupying different parts of western North America interacted. In this paper we apply a landscape approach to study pre-contact projectile point morphologies and raw materials, and related changes in the geographic affiliations of peoples using the Billy Big Spring Site, located near the Front Ranges in the Blackfeet Indian Reservation of Montana. This site contains numerous points recovered in chronostratigraphic contexts ranging in age from Late Paleoindian to Late Precontact. The sample includes types and raw materials alternatively typical of the Rockies/Plateau, the Front Ranges, and/or the Plains. Variation in the projectile point record at Billy Big Spring is consistent with the notion that, as observed in the recent past, information networks spanned a wide geographic area that englobed the Plains, the Front Ranges, and the Plateau/Rockies during most of the pre-contact period. Exceptions and changes in the geographic affiliations of people using the site can in turn be related to major environmental and demographic events that occurred in the region.