Paleoecological reconstructions of the corridor indicate that it was a harsh, resource-poor environment during the period of maximum glaciation and the early phase of deglaciation.

It may not have become a viable migration route until after 13,000 to 14,000 years ago — after the time when people were clearly present in South America and therefore after the initial southward expansion must have occurred.

This chronological mismatch has strengthened the case for a coastal migration route as the primary pathway of the initial peopling.

The Pacific coast of Beringia and North America offered a productive, resource-rich environment — the kelp ecosystem supported fish, shellfish, marine mammals, and seabirds — that could have sustained a mobile coastal people moving southward even during the period of maximum glaciation.

The coast was also largely ice-free south of a certain latitude, unlike the interior, which was buried under ice.