Saguaro National Park

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The Sonoran Desert landscape of Saguaro National Park against the Santa Catalina Mountains. Photographed 03/2008 near Tucson Arizona.

Saguaro National Park preserves nearly 100,000 acres of pristine Sonoran Desert wilderness. This park is divided into eastern (Rincon Mountain) and western (Tucson Mountain) districts on either side of Tucson, Arizona. Back in 2008 I got to visit the impressive Rincon Mountain district on a college geology trip.

Saguaro protects an environment filled with unique organisms including the saguaro cactus (Carnegiea gigantea, Cactaceae). Pronounced “sa-WAH-ro”, this largest North American cactus is ubiquitous in the park:

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Saguaro cacti photographed 03/2008 at Saguaro National Park, Arizona.

Although slow-growing, these plants can live for over 150 years and grow to up to 60 feet in height.

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Saguaro cactus photographed 03/2008 at Saguaro National Park, Arizona.

Saguaros are often depicted with side arms, but these features are limited to mature individuals. Several decades of growth take place before side arms develop. Before then these cacti are relatively unimpressive spears:

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Saguaro cacti photographed 03/2008 at Saguaro National Park, Arizona.

Many other plants fill the desert landscape at this national park, and unsurprisingly most are cacti. Other common species include the pinkflower hedgehog cactus (Echinocereus fendleri, Cactaceae)…

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Hedgehog cacti photographed 03/2008 at Saguaro National Park, Arizona.

fishhook barrel cactus (Ferocactus wislizenii, Cactaceae)…

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prickly pear cactus (Opuntia sp., Cactaceae)…

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Prickly pear cacti photographed 03/2008 at Saguaro National Park, Arizona.

teddy bear cholla (Opuntia bigelovii, Cactaceae)…

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Teddy bear cholla photographed 03/2008 at Saguaro National Park, Arizona.

…formidable ocotillo (Fouquieria splendens, Fouquieriaceae)…

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Ocotillo photographed 03/2008 at Saguaro National Park, Arizona.

…and aromatic creosote bush (Larrea tridentata, Zygophyllaceae):

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Creosote bush photographed 03/2008 at Saguaro National Park, Arizona.

I also found multi-colored lichens clinging to the local rocks:

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Multi-colored lichens photographed 03/2008 at Saguaro National Park, Arizona.

The geologic history of these Rincon Mountain rocks goes back nearly two billion years. Ancient volcanic and sedimentary deposits were subjected to intense heat and pressure during continental collision, altering their physical composition. This metamorphic core complex was subsequently buried by younger sediment, only to be exposed again over hundreds of millions of years of uplift, erosion and extension. The Precambrian banded gneiss was particularly obvious:

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Banded gneiss photographed 03/2008 at Saguaro National Park, Arizona.

Among the rocks there was the promise of javalinas, also known as collared peccaries (Pecari tajacu, Tayassuidae). Since we camped that night up in the Santa Catalina Mountains, however, we didn’t get to see any of these pig-like creatures:

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Javalina Rocks sign photographed 03/2008 at Saguaro National Park, Arizona.

Although the various impressive cacti took center stage on this visit, there are many more fascinating plants, animals, and rocks to see here. As with other national parks, a longer visit would definitely expand on an already satisfying trip.

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The Sonoran Desert landscape of Saguaro National Park against the Santa Catalina Mountains. Photographed 03/2008 near Tucson Arizona.

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About Jeremy Sell

Science and nature nerd.
This entry was posted in Botany, Geology, National Parks, Vertebrate Zoology and tagged , , , , , , , . Bookmark the permalink.

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