The Phoenix Zoo opened in 1962 and is the largest privately owned nonprofit zoo in the United States. Located in Phoenix, Arizona, the zoo was founded by Robert Maytag, a member of the Maytag family, and operates on 125 acres (51 ha) of land in the Papago Park area of Phoenix. It has been designated as a Phoenix Point of Pride. The zoo has over 1,400 animals on display and contains 2.5 miles (4.0 km) of walking trails.

From Wikipedia