Nice piece.
The stones appear to be genuine. I recognize Turquoise, Lapis Lazuli and what appears to be Aquamarine. Assuming they are genuine, I'll bet they are from one of the Southern Utah tribes. Probably Navajo. There is a website that sells similar jewelry called Cowboy and Indians Jewelry. I can't give the URL directly, but that should give you a starting point. Contact them and see what they have to say.