[2] Upward Sun River is the site of the oldest human remains discovered on the American side of Beringia.
Some artifacts found include microblades, small wedge-shaped cores, some leaf-shaped bifaces, scrapers, and graving tools.
Paleo-Arctic stone specialists also created bifaces that were used as tools and as cores for the production of large artifact blanks.
The Nenana Complex is the oldest part of the Paleo-Arctic Tradition found in cultural stratigraphic layers dating from 11,800 to 11,000 BP.
The complex also includes bifacially worked knives and unifacially retouched lithic flakes lacking microblades that generally resemble similar lithics found in sites of the Kamchatka Peninsula in Russia, possibly due to migration and cultural exchange over the Bering land bridge.