Before discoveries such as Cooper's Ferry, Clovis stone tools, generally about 13,000 years old, were considered the earliest human technology in the Americas.
Notes on verification
Confirmed by multiple independent sources including Wikipedia, Archaeology Magazine, and Oregon State University press release on Cooper's Ferry findings. [cascade flags: wikipedia_dropped_other_sources_exist | tier=silver indep_score=0.875 clusters=2 claim_tier=notable]
Sources
- 15,000-year-old Idaho archaeology site now among America's oldest (seed:history_and_archaeology)
- https://news.oregonstate.edu/news/new-artifacts-suggest-first-people-arrived-north-america-earlier-previously-thought (corroboration)
- https://www.archaeology.org/issues/366-2001/trenches/8240-digs-idaho-coopers-ferry (corroboration)