Tonto National Forest

The Tonto National Forest, encompassing 2,873,200 acres, is the largest of the six national forests in Arizona and is the ninth largest national forest in the United States. The forest has diverse scenery, with elevations ranging from 1,400 feet in the Sonoran Desert to 7,400 feet in the ponderosa pine forests of the Mogollon Rim. The Tonto National Forest is also the most visited "urban" forest in the United States.The boundaries of the Tonto National Forest are the Phoenix metropolitan area to the south, the Mogollon Rim to the north and the San Carlos and Fort Apache Indian Reservation to the east.

Source: Wikipedia