The lowest levels of the Simonsen site produced projectile points, scrapers, and knives in association with Bison occidentalis. The level is dated by radiocarbon at 6471 B.C. ± 520 years. The triangular, side-notched, and concave-based Simonsen point resembles points from the Turin and Hill sites in Iowa and the Logan Creek site in Nebraska. The close resemblances between the collections from the Simonsen site and the Logan Creek site, which is also radiocarbon dated, provide a basis for dating the essentially similar preceramic material from the Turin and Hill sites.