See, North America is quite straight forward to sort out.
During the last Ice Age, sea levels were 100m lower than now.
You guys in the UK had Doggerland. Peoples went east/west with great ease.
Here in the west was a huge piece of land across Alaska and Siberia called Beringia.
Humans stayed there for maybe 10,000 years before the ice receeded.
The glaciers melted here at my place about 8,000 yrs BP.
Then people that we call "First Nations" began to populate the Americas.
The oldest Heiltsuk village on the coast of BC is 14,700 years old.
These First Nations are 4 maternal blood lines, called A, B, C and D.
The fifth one on the east coast is E (Scandanavian maternal no less)
The sub-haplotypes have been identified by the dozen in the past decade.
Your Neolithic paleo peoples are nearly lost in the fog of history.
No so here. Anglo contact is just 3 centuries ago. They had to sail all around South America to get here.
Maybe older if the FN were trading with the Chinese or Russians that sailed the Japan Current to the west coast of the Americas.
Haida, Tlingit and Tsimshian are still growing Peruvian potatoes.
Somebody went there. . .. . .. but nobody admits to licking the plates.
? 
