Clovis and Western Stemmed: Population Migration and the Meeting of Two Technologies in the Intermountain West

The Intermountain West is rarely included in discussions of the North American Paleoindian record, largely because there is so little evidence for Clovis in that region. What has been ignored in these discussions is the presence of an early record in the region associated not with Clovis, but with a different technology, the main diagnostic of which is the large, contracting stemmed projectile point. Dates associated with this technology are comparable to the earliest Clovis dates on the Plains. An examination of the spatial and temporal distributions of Clovis diagnostics suggests that elements of this technology arrived relatively late in the Intermountain West, apparently the termination of a diffusion (or migration) process that began in the southern Plains or Southeast, moved northward along the Rocky Mountain front, and eventually onto the Columbia Plateau. We argue that initial colonization of the intermountain region most likely involved groups moving inland from the Pacific coast carrying a non-Clovis technology, which was already in place by the time Clovis technology arrived.