So called 'indigenous people' got there from somewhere, most likely from Asia. Indigenous people did not spring up in the Americas spontaneously.
Indigenous people were far from the pot smoking existentialist hippies as the Left portrays them. They were murderous warriors. They had cannibalism, human sacrifice, slaves, and never ending territorial wars. They stole women, children, property, resources, food, tents, land, slaves, and whatever they could take from each other. The only reason one or an alliance of tribes did not rise to dominate the entire continent is because they were all equally armed and were all living in the 'stone age'.
They would run entire herds of deer, elk, buffalo off a cliff and would only take whatever they could carry and use. The idea that indigenous people were tree hugging environmentalists is an insane distortion of history. Yes, they did less damage to the environment but that was not by choice. They did less damage because they were living in a society similar to 5000B.C. and could not possibly do as much damage as a modern society. If they could have they would have. There are no Luddite indigenous people.