A sampling of some of the scores of artifacts produced by First Americans at the Cooper’s Ferry site in western Idaho. Dotted lines along some of the tools indicate patterns of wear. (Credit: Davis et al 2019)

Stone tools, charcoal and other artifacts from Cooper’s Ferry, Idaho, are the latest evidence that the First Americans arrived more than 16,000 years ago — well before an overland route existed. It’s looking more and more likely the first people arrived via a Pacific Coast route.