It is not perfect — no archaeological evidence of this kind ever is, and honest researchers acknowledge the specific remaining uncertainties.

But it is the kind of evidence that comes from a claim that has been tested from multiple directions and has emerged from each test with its core interpretation intact and supported.

The central finding — that people were in the Oregon Great Basin before the conventional Clovis horizon, approximately 14,200 years ago, carrying the founding maternal lineages of Native American ancestry — is supported by directly dated biological specimens, confirmed by independent DNA analysis, corroborated by fecal lipid biomarker chemistry, consistent with a dense network of associated radiocarbon dates, and accompanied by a contemporaneous lithic technology distinct from Clovis.

This is strong evidence.