Tumamoc Hill

I finally got my act together and made my first ascent of Tumamoc Hill, just west of downtown Tucson, on Easter Sunday, April 4, 2010. The public is only permitted on the property during weekends, and you must stay on the paved road at all times. Why? Well, this particular parcel of land has a very unique history.

The sign pictured above reads: University of Arizona Desert Laboratory, founded in 1903 as the Carnegie Desert Botanical Laboratory, Tumamoc Hill, United States Geological Service. Indeed, this butte has served as a living laboratory for a very long time, and non-university and non-government personnel need to be restricted to protect the study plots. Consequently, the area is closed to the public weekdays from 7:30 AM to 5:30 PM. The hill is very popular with the exercise-minded on weekends. Birdwatchers, botanists, and nature lovers in general also visit. I spotted this Cooper’s hawk while at the summit.

The Carnegie Institution of Washington chose this site to establish an ongoing study of the adaptation of plants to aridity, beginning in October, 1903. That mission continues to this day. The University of Arizona purchased the facilities (several buildings occupy the area) in 1956 to house their new department of geochronology.

Meanwhile, the United States Geological Service (USGS) conducts two major long-term projects: Biotic response to climate variability; and Landscape change in the Southwest.

Walk all the way to the top and you might see a flock of white-throated swifts, or some of the insects they are feeding upon. You will also be treated to some pretty stunning views of Tucson (with the Rincon Mountains in the background), and the Santa Catalina Mountains.

The entire butte is 860 acres (3.5 square kilometers), but 320 acres, including a handful of study plots, changed hands in February, 2009. This came as a result of a state trust land auction in which Pima County made the winning bid (and only bid). Prior to that, Tumamoc Hill was more or less the poster child for a movement to reform state trust land policies. A 2006 effort to change the state trust land system via a state constitutional amendment failed.

Human occupation of this site actually dates back as far as the Hohokam tradition of the Native American Southwest. With any luck, our collective footprint on Tumamoc Hill will continue to be relatively light, while continuing to shed light on the changes in climate, flora, and fauna here.