The sites that a coastal migration population would have occupied are, for the most part, under water.

This is a fundamental limitation on the archaeological record of early American settlement that cannot be overcome by any advancement in land-based archaeological methods.

Underwater archaeology can, in principle, investigate submerged sites — there are examples of submerged prehistoric sites in other parts of the world that have been investigated by underwater archaeological methods — but the conditions of the Bering Sea, with its cold temperatures, strong currents, and limited visibility, make submerged site investigation particularly challenging.

The absence of archaeological evidence from the Beringian land bridge is therefore not evidence that no one lived there.