History of Phoenix, Arizona
The history of Phoenix, Arizona, goes back millennia, beginning with nomadic paleo-Indians who existed in the Americas in general, and the Salt River Valley in particular, about 7,000 BC until about 6,000 BC. Mammoths were the primary prey of hunters. As that prey moved eastward, they followed, vacating the area.
Source: Wikipedia — History of Phoenix, Arizona (CC BY-SA 4.0)