For one thing, it's incredibly chauvinistic to dismiss pre-colombian society as "some nomads," and their mobility patterns as having "wandered". Nomadic life-ways aren't the thoughtless ramblings of a child at play, or a sub-sentient beast in simple reactionary pursuit of greener pastures. They summer here, winter there, raise children in these parts, and visit those for sport, trade, or agriculture. Their relationship with the land is purposeful, and maintained by cultural artifacts we'd recognize as Almanacs.
One isn't "wandering" just because they haven't poured concrete.
For another thing, the pre-colombian americas weren't the Gardens of Eden, magically and effortlessly producing sustenance, and materials for us to enjoy. They were cultivated, sculpted, and gamed into those forms which facilitated our survival. There's evidence enough of that in the ways that restrictive intra- and under-growth have returned to the forests indigenous populations kept pruned for their traversal.
Lastly, biomes are big systems, and interconnected. I may have only a small garden, but it's fed from massive watersheds. If I am to survive, the mountains which constitute that watershed must be recognized as "mine" in some regard. So it goes with all the lands which feed into, and out of, those through which "some nomads once wandered."
I hope you can see, now, how myopically your "reality check" frames the situation.
Edit: I took out a specious allusion to the BLM.