Could you go more in depth on that since they were on near-opposite ends of the continent? Was this after the "Trail of Tears"?
In the early years of the distribution of tribes across the land, each nation was at war with each other. Boundaries were strictly observed where skirmishes were commonplace. Continuous warfare, however, made territory fungible. Whole nations were driven out of areas and forced to travel a “Trail of Tears” in search of uncontested land.
By the time settlers began arriving so called native nations had been decimated by disease, warfare, and slash and burn environmental disasters. As a result they posed little real treat to early European settlers.
It has only been in the 20 century with the support of Western culture that populations of early native people have rebounded and exceeded all earlier numbers. There are larger numbers of early native people on this continent today than ever existed.