ARCHAEOLOGY IN TUCSON
Vol. 12, No. 3
Newsletter of the Center for Desert Archaeology
In Search of El Presidio de Tucson
J. Homer Thiel, Desert Archaeology, Inc.
t is easy to forget, as one views the skyline of modern Tucson, that our community has its origins in a small Spanish fortress. In 1775, Captain Hugo O'Conor selected a piece of land on the east side of the Santa Cruz River for a presidio. Over the next eight years adobe walls were built I
to enclose the
Today the walls are lost, buried ,in the heart of Tucson below streets, lawns, sidewalks, and buildings. In order to find them, we must examine historic documents and old photographs, excavate trenches, and study artifacts.
Over the last 10 years, the Center for Desert Archaeology has initiated several research projects to look for remains of Tucson's Presidio. In 1991 we worked with
carefully screened dirt and bagged artifacts. Undisturbed archaeological deposits were found in most areas. Especially exciting was the discovery of a complex of features in the lawn area on the west side of the City Hall.
The Presidio of Tucson
The walls of the Presidio were reported to have run along Washington Street on the north, Church Street on the east, Pennington Street on the south, and Main Avenue on the west. Each side of the Presidio was about 750 feet long. The wall was reported to have been between 18 inches and 4
thick and between 6 and 16 feet We have no contemporary
rely on accounts preserved in the 1920s and 1930s and,
by people as a result,
Inside the fortress were homes, barracks, and stables built against the interior walls, a cemetery and church
Map of the trench excavated in the west lawn of the Tucson City Hall (prepared by Geo-Map, Inc.). on the east side, a commander's house in the center, and several plazas. A Karl Glass of the University of Arizona on a ground-penetrating pair of gates pierced the west and east walls, roughly where Alameda Street meets Main Avenue and one on Church Street at Alameda. The wall helped protect the community against attacks by Apaches, but by the 1850s this threat had subsided and the wall was demolished, with many of the bricks serving as building materials for Territorial period homes. The first map of Tucson, drawn in 1862, appears to show the general outline of the wall, especially the north and east sides. The last known standing portion of the wall was torn down in 1918. radar study that suggested that portions of the Presidio wall were intact beneath the ground surface in several areas. The following year, Center volunteers helped excavate trenches in the Pima County Courthouse courtyard, ultimately exposing a north-south adobe wall which rests on a stone foundation (see AIT, July 1993). This is thought to be the east Presidio wall, perhaps a portion dating to the remodeling of the wall in the 1820s. The City of Tucson recently acquired the northeast corner area of the Presidio, which lies beneath a parking lot. The City and Pima County have ordinances protecting cultural resources; however, development activities, such as utility installation, can still impact Presidio period archaeological remains (AIT, April 1992). A better understanding of what lies buried beneath the ground will aid in the development of a master plan for the Presidio area, helping guide future activities. A North-South Wall The earliest historic feature found was a segment of a north- to-south adobe brick wall. The surviving portion of this wall was built from pinkish-brown adobe bricks, each measuring 19 inches long, 11 inches wide, and 4 inches thick. The bricks were plastered together with a gray-brown mortar. Two courses rest on a wider foundation that is about 32 inches wide and consists of three adobe bricks resting side-by-side, held together by a In March and April 1998, the Center returned to search for portions of the south, west, and north walls of the Presidio. Trenches were excavated in five areas by volunteers who lighter-colored The basal of bricks mortar. course was