Microblades are a distinctive technological innovation with a specific geographic and temporal distribution.

They appear in northeastern Asia and in Alaska at similar time periods, and their presence in the Alaskan archaeological record reflects technological connections between the founding population of the Americas and the northeastern Asian populations they had separated from.

The Denali Complex, to which the Upward Sun River tools belong, is regarded as a North American expression of a broader Beringian technological tradition.

The presence of this technological tradition at Upward Sun River 11,500 years ago — in the same site where USR1’s remains were found — does not prove that USR1’s community made the specific tools.