Plants and Petroglyphs in the Sonoran Desert
Saguaro National Park was the first national park established to protect a plant species. It is named after the saguaro cactus.
Saguaro National Park is actually made up of two separate areas. Saguaro East is in the Rincon Mountains and Saguaro West is in the Tucson Mountains. The City of Tucson lies between them.
When you ask a child to draw a cactus, they draw a saguaro. The tall post-like center with branching arms has become the symbol of a cactus. In reality, saguaros (Carnegiea gigantea) have a narrow range. They grow only in parts of the Sonoran Desert, which is in Arizona, Baja Mexico and a small part of California.
Saguaros require rocky soils, more precipitation than typically occurs in deserts, and mild temperatures without prolonged freezing.
Saguaros grow very slowly–only an inch or so during their first six to eight years. It might take 70 years before they sprout branches or arms. They don’t reach their full height, 40-50 feet, until the age of 150.
Adapted to Desert Life
Saguaro National Park receives approximately 13 inches of rain a year. (A typical desert receives 10 inches or less.) To maximize water absorption, the shallow roots of the saguaro extend as far outward as the trunk is tall.
As saguaros soak up water, the accordion-like pleats on their trunk expand to store the moisture in their spongy flesh.
The saguaro doesn’t have leaves, but conducts photosynthesis through its green trunk. A waxy skin reduces moisture loss. Spines shade the plant, shield it from drying winds and protect it from animals. Their “skeleton” is in the center and made up of woody ribs.
Saguaros are Vital to their Ecosystem
Saguaros are a “keystone species.” This means that this plant defines their ecosystem and, without its presence, the ecosystem would be dramatically different or not exist.
The saguaro trunk provides a home for many animals. Gila woodpeckers and gilded flickers drill nest holes in the trunks. Abandoned holes become homes to elf owls, screech owls, purple martins, finches and sparrows.
Raptors, such as the Harris and Red-tailed hawks, build nests on the saguaros. When they leave, ravens and great horned owls move into the nests.
Food is precious in a desert, and the saguaro feeds birds, rodents, mammals and insects. Their cream-colored flowers appear in early summer. Their nectar feeds their pollinators, the lesser long-nosed bats, white-winged doves, honey bees, and moths.
In July, the red fruit ripens and provides food for doves, bats, jaelina and fox. Pack rats and jackrabbits eat the flesh of the cactus.
Indigenous People of Saguaro National Park
The Saguaro forest was home to the indigenous people called the Hohokam and their descendants, the Tohono O’odham.
The Tohono O’odham traditionally harvest saguaro fruit when it is ripe, usually in late June, for the Nawait I’i (Rain Ceremony), which occurs just before the monsoon season. The fruit is used to make candy, saguaro wine, jams and jellies. Historically, the saguaro provided a vital source of food and drink when the desert was driest.
Petroglyphs Created by the Hohokam
The petroglyphs are one of the most amazing things in Saguaro National Park. Petroglyphs are in both the East and West sections.
People of the Hohokam culture pecked and scraped designs into the rocks between 450-1450 CE. The Hohokam used a stone chisel and a hammerstone to chip away the dark desert varnish on the rocks to create the petroglyph. The petroglyphs are thousands of years old and their meanings are unknown.
Images of America: Saguaro National Park
“Realistic and abstract forms included stickmen, bighorn sheep, zigzags, spoked wheels, mazes, and the magnificent spiral at Signal Hill…Some appear to be markers for the equinoxes and the summer solstice.”
Saguaro National Monument Becomes a National Park
Since the 1800s, tourists had been visiting the Tucson area to see the magnificent saguaros. Citizens and naturalists knew that the unique plants needed to be protected.
Saguaro National Park East–Rincon Mountain District
Saguaro East was declared a National Monument in 1933, by President Herbert Hoover. Although Hoover is now remembered for his leadership failures during the Great Depression, he also was an engineer, a conservationist and an avid fisherman.
Saguaro East has Mica Mountain at a 8,666 foot elevation and has some snow in the winter. This section of Saguaro National Park has a variety of habitats including grasslands, oak-pinyon-juniper woodlands and a coniferous forest dominated by ponderosa pine.
Saguaro National Park West–Tucson Mountain District
Saguaro West has an elevation beginning at 2,180 feet and has many different types of cacti. Saguaro National Park West was established in 1961.
Both the east and west parks graduated from National Monument status to become Saguaro National Park in 1994, by President Clinton.
Importance of National Park Protection
When preservation efforts began, the main risk to the saguaros was from ranchers. The livestock trampled young saguaros and overgrazed.
However, in modern times it is clear that the biggest risk to the saguaro ecosystem is urban sprawl from Tucson. The black part of these maps show how much Tucson has grown each decade and the 2030 forecast. We are lucky that politicians and conservationists of the past had the vision to protect 91,327 acres of incredible biodiversity.
Other Sites to See Near Tucson
The Arizona-Sonora Desert Museum is located within Saguaro National Park West. This is a zoo with sections devoted to the plants and animals found in the Sonoran Desert. It is amazing. If you are traveling with kids you must explore it. Visit early in the morning because it gets crowded and hot.
Consider taking a historic bicycle tour of Tucson to get a nice overview of the area and discover its neighborhoods. I did this years ago and it opened my eyes to wonderful little treasures in the City that I never would have found on my own.
The City of Tucson has a charming downtown near the historic Hotel Congress.
On Court Street, you can find the oldest Mexican restaurant in America. It is called El Charro Café and the food is incredible.
Historic Fourth Avenue has terrific shops for you fellow retro lovers. If you didn’t get enough plant-love, be sure and check out Tucson Botanical Garden. This garden combines art and thematic xeriscape plantings. It has an incredible butterfly house.
Barrio Brewery is in the old warehouse district and it has great beer and terrific food for a good price.
If you want to have a desert-themed vacation, look for prickly pear drinks and Mexican dishes with a cactus called Nopales. These are available in many restaurants throughout the City.
Saguaro National Park is an uncrowded gem in the National Park system. The views of cactus and mountains are accompanied by birds singing. While there, visit the City of Tucson for a perfect Retro Road Trip.