The second is the coastal route — movement along the Pacific coast of Beringia and North America, following the productive kelp ecosystem that the coast supported.

The ice-free corridor route is well-documented as a geographic reality.

The corridor existed, it connected Alaska to the interior of the continent, and it was eventually traversed by people — the Clovis people and their successors clearly used the interior of the continent.

The question is whether the corridor was available early enough, and whether it was ecologically productive enough, to support the passage of the founding population during the initial peopling of the Americas.

The evidence increasingly suggests that the corridor was not available or productive enough during the very early period of human entry — roughly 20,000 to 14,000 years ago.