[SauronOfMordor]

That points out a problem with the Bering land bridge that people supposedly walked across last Ice Age. It was a thousand miles of desert. A major expedition might make it across, but a hunting party would not be interested.

A fishing society might have been more likely to have been moving along there

[RightWhale]

The middle of Alaska is still kind of a desert and there is little wildlife. Granted a moose here and there gives the impression of lots of wildlife. There are fish. The early settlements were along the coast and relied on fishing and mammals that fish. Small coastal fishing boats was probably the main way people got around, since you can hardly walk across the muskeg ground in summer. It's hard to imagine hunters walking across just to find themselves in more desert.