Cooper’s Ferry was excavated and published by a team led by Loren Davis of Oregon State University.

The site produced a stratified sequence with multiple occupational phases, well-preserved organic material for radiocarbon dating, and a stone tool assemblage that includes projectile points and other tools.

Multiple radiocarbon dates on the site’s earliest occupation levels consistently returned ages older than 15,000 calibrated years before present — substantially predating the Clovis horizon.

The significance for the broader debate is considerable.

Cooper’s Ferry provides well-dated, multiply redundant evidence for human presence in the Snake River Plain system before Clovis.