The Mountain


What is Tumamoc Hill?

It’s a highly protected wild-lands Sonoran Desert mountain, National Historic Landmark, ecological research preserve, U.S. Archaeological District, and community icon, all of two miles from downtown and surrounded by growing urban Tucson.

But there is no single description of Tumamoc Hill that is complete. There are many layers to the place, with different meanings depending on who you are.

A geologist will tell you that Tumamoc is an inselberg of volcanic rock remaining from eruptions between 20-30 million years ago. It originally was formed near what is now the Santa Catalina Mountains.

A paleontologist will tell you that the current Sonoran Desert environment came about 8-15 million years ago during a drying trend when the unique desert plants here evolved from tropical ancestors moving north from Mexico. Tumamoc Hill is an 860-acre bounded bubble of that Sonoran Desert that is still changing and evolving. Ecologists have made the whole Hill their laboratory.

The Tohono O’odham call it Cemamag Doag, or “Horned Lizard Mountain.” The Hill is considered a sacred ancestral site for O’odham, Pascua Yaqui, and Hopi Indians. Ancient people first occupied the summit village in 400 BCE. The Hill has been a gathering place for people in the Tucson valley for 24000 years.

The mountain has been called many names. Lawrence Clark Powell, famed librarian, and writer who lived in Tucson called Tumamoc Hill “Tucson’s Acropolis.” It’s been called by various names, including “A Mecca for botanists”, and “The Jerusalem of desert rats.”

The first thing a modern ecologist might say to you is “don’t stray off the road.” Beginning with the establishment of the Desert Botanical Laboratory in 1903 by the Carnegie Institution of Washington, Tumamoc is the oldest continually monitored ecological research preserve in the world, with data from over 100 years of study. This is the world’s first restoration ecology project. The landscape here is to look at, to study, to appreciate the beauty, but not to exploit. Not even to use.

Desert Botanical Lab on Tumamoc Hill 1911

To an archeologist, Tumamoc is a mystery that would challenge even Sherlock Holmes. Ruins of cultures living on Tumamoc go back 3,500 years, and at various times in prehistory, the Tumamoc hilltop was probably an important landmark, cultural focal point, and ceremonial ground.

To the thousands of people who walk the road daily, Tumamoc is the best workout in town, a treadmill with a spectacular view. It’s a source of healing and health. It’s a place for an evening paseo with friends. One can stroll among grazing deer five minutes from downtown. Dig a little deeper and many walkers will confide that Tumamoc is a personal emotional or spiritual sanctuary.

Urban culture and ecological research can co-exist on Tumamoc Hill. It is a sanctuary for humans as well as other Sonoran Desert life forms, and the boundaries are clear: no one steps off the road without special permission. Scientists have protected the Hill for the last century. Now it’s up to the community to take part in the stewardship of the Hill as a special place because having a wild patch of desert is a cultural value.

We’ll check in again in a hundred years to see how it’s going.

View of the Tumamoc Desert Lab at sunset
The Desert Laboratory on Tumamoc Hill