Maps like these give the false impression that nearly every square mile of land - even inhospitable desert regions, were once occupied by some native polity. Reality check: Most indigenous peoples lived in Mesoamerica, with < 10 million in what is now USA/Canada and that's being generous. There are regions of North America today that have no residents. By what grounds are these native lands - because some nomads once…
Maybe no one owns the land then? Owning land by purchasing a title registered in the State's land registry can hardly be a stronger claim than being a nomad wandering through.
And just for some additional context, nearly all Native North Americans share the same ancestral DNA.