Officially designated in 1994, Saguaro National Park was the 52nd established American National Park. Located in the Sonoran Desert of southern Arizona, the park is home to the giant saguaro cactus, the "king" of all cacti. While these cacti can grow to over 40 feet tall, their root system can extend to a diameter up to 100 feet at a depth of only inches. Saguaro National Park is split into two parts: The Rincon Mountain District, located to the east of Tucson, and the Tucson Mountain District to the west. Combined, these two districts give the park an area of nearly 92,000 acres.