Saguaro National Park gets its name from the saguaro, a large cactus, which is native to the region. Saguaro are native only to the Sonoran Desert, and only in certain parts of southern Arizona and northern Mexico where the conditions are right
Saguaro National Park has two sections, which are called districts. The Rincon Mountain District is located to the east of Tucson and the Tucson Mountain District is located to the west of Tucson. The two districts encompass over 91,000 acres, of which almost 71,000 acres are designated wilderness. Each district has a visitor center and each center can supply a map of hiking trails in the park.
The Eastern Rincon Mountain District of Saguaro National Park rises to over 8,000 feet and includes over 128 miles of trails. A feature of this district is its 8.3-mile loop road, which provides access to the two picnic areas and the central trails. Hiking on this side of the park is readily accessible to visitors. There are trailheads at the east end of Speedway and Broadway and these are popular with equestrians, especially on weekends. There are several additional trailheads off the park’s loop road. There are no campgrounds accessible by road in the park, but the Rincon Mountain District is open to backcountry camping at designated sites. A wilderness permit is required for all overnight stays.
The Western Tucson Mountain District of Saguaro National Park is lower in elevation than the Eastern Rincon Mountain District and has a denser saguaro forest. This section of the park is smaller and biologically younger than the east section but the saguaros are just as large and extensive. The north and west areas are generally flat with uninterrupted forests of the huge cacti, while the land becomes more mountainous towards the south and east, rising to a high point of 4,687 feet.
Saguaros are a very slow growing cactus, often growing no more than 1.5 inches in the first eight years of its life. The young saguaros grow under the protection of a tree, most often a palo verde, ironwood or mesquite. As the saguaro continues to grow, its much older protective tree may die from old age or because the saguaro is taking water and nutrients from the surrounding soil.
When a saguaro reaches 35 years of age it begins to produce flowers. Though normally found at the terminal end of the main trunk and arms, flowers may also occur down the sides of the plant. Flowers will continue to be produced throughout a saguaro’s lifetime.
At Saguaro National Park, branches normally begin to appear when a saguaro reaches 50 to 70 years of age. In areas of lower precipitation, it may take up to 100 years before arms appear. With the right growing conditions, it is estimated that saguaros can live to be as much as 150-200 years old and grow as tall as 60 feet. The saguaro soaks up water when it rains. When rain is plentiful and the saguaro is fully hydrated it can weigh between 3,000-5,000 pounds.
Click here for the Saguaro National Park website.