The Cooper’s Ferry evidence suggests that people were using the Pacific drainage system of western North America — following the rivers that connect the inland plateau to the Pacific Coast — well before the Clovis tradition was established.

The Paisley Caves in the Warner Valley of Oregon have produced human coprolites — preserved feces that contain ancient DNA — with AMS radiocarbon dates in the range of approximately 14,000 to 14,500 calibrated years before the present.

The coprolites carry the genetic signature of Indigenous American people, establishing human presence in the Great Basin region of Oregon before Clovis.

The Paisley Caves evidence is biochemical rather than artifactual, but it provides a different kind of confirmation — the literal biological trace of a human being — for pre-Clovis occupation.