NPS Photo by David Yubeta
Historic Preservation at Tumacácori National Historical Park
It takes a tremendous amount of knowledge and skill to properly preserve the park's historic adobe structures.
Each year, 2500 staff hours are spent in preparation for field work. This includes assessing the work that needs to be done, priortizing preservation projects, purchasing materials, planning logistics, and communicating with partners to clarify the goals of each preservation project. It is during this process that unforeseen problems are brought to the table and past experiences are reviewed to improve the quality of preservation work. Reports are completed after each project that will serve as future reference. Additional time is spent training new staff and outreach to local educational institutions.
Another 2500 staff hours are spent each year on "hands-on" field work to maintain the structures at the park's mission sites of Tumacácori, Calabazas, and Guevavi. Materials used for preservation are the traditional types of materials that were originally used to build the missions. Appearance of each work site is documented before and after each project.
The most typical size of an adobe, i.e. "a dried-mud brick" at Tumacácori’s Franciscan church is 12x3x24 inches.
More than 90,000 adobes were used to build the present historic church.
Fired or cooked adobe bricks were used where strength was needed for support, such as in the bell tower.
Lime plaster was the traditional covering for adobe structures, consisting only of lime, from limestone, water, and sand.
It is estimated that over 20 million dollars have been spent on the missions' preservation since 1917.