The kelp highway hypothesis proposes that the primary route of the initial peopling of the Americas was along the Pacific coast, not through the ice-free interior corridor.

The productive marine ecosystems of the North Pacific coast — the kelp forests that support dense populations of fish, shellfish, marine mammals, and seabirds — would have provided a rich and reliable food source for people moving southward along the coast.

The coast was largely ice-free south of a certain latitude even during the Last Glacial Maximum, unlike the interior of the continent, which was covered by glaciers.

And the coast offered a relatively direct path from the Beringian source region to the southern tip of the Americas.