Arizona and South Dakota.
Arizona is the state with probably more Native American reservations than any other. We could name a couple such as the Navajo Nation, Tohono O’odham Nation, San Carlos Apache Reservation, Hopi Tribe, Colorado River Indian Tribes, among many others. A fun fact is that with such an amazing diversity of Indian culture, Arizona has one-fourth of its territory occupied by more than 20 reservations!
Second to Arizona, South Dakota is also one of the states with an outstanding abundance of Indian American reservations, among which we can find, the Pine Reach Indian reservation, the Flandreau Indian reservation, the Rosebud Indian reservation, and others.