As many have pointed out, below the Rio Grande we see thriving examples of native peoples, languages, and cultures surviving. Now, this is largely due to a couple things:
1. These were the most densely populated areas of the Americas.
2. The existence of bureaucratic governmental systems the Spanish could co-opt.
3. Survival through assimilation, and isolation. (Adoption of Catholicism with many native influences, and the unforgiving environment protecting large scale incursions by settler colonies)
Thus, either one can (as others have stated), make a Pre-contact point of divergence whereby North America sees the same level of urbanization and state building as Central and South America. Or, I'll propose a post contact POD.
Would earlier exploration, and settlement of the North American continent provide for an increased chance at survival? I want to say yes, maybe, hopefully if things go a certain way.
When Cortes and Pizarro conquered their respective foes, not only were they incredibly lucky, they also were not that advanced in technology and ability as most people like to project. It was the early 1500s, Europe was not the world conquering beast that it turned into by the time the North American colonies really got going (almost 100-200 years later).
If the Iroquois, Huron, Alqonquin, Cherokee, Cree, and plenty of other indigenous groups were being contacted with 100-150 years prior then they were by the East Coast settler colonies we could see:
1. Increased failure in those colonies, forcing the Europeans to cooperate with natives more
2. More contact, more guns, more time for the Natives to acclimate with these new comers, but not be behest to the explosion the early Industrial Revolution caused.
But, that is just one possible, but maybe not probable way to do this with a post contact POD.