The evidence was not pollen or phytoliths or sediment chemistry — material that is real but requires multiple steps of interpretation to connect to human presence.

The evidence was footprints — the direct, physical, anatomically specific trace of human bodies moving across an ancient surface.

You cannot misidentify a well-preserved human footprint as a natural geological feature.

The anatomy is too specific: the characteristic elongation, the narrowing at the arch, the widening at the ball, the individual toe impressions in the better-preserved examples.

Natural geological processes do not create these features in soft sediment.

The identification of the White Sands trackways as human was, unlike many pre-Clovis claims, not a matter of serious dispute.