Statement of Significance (as of designation - October 9, 1960):
Founded in 1700 by the Jesuits, Bac then formed the extreme northern thrust of Nueva Espana. The present structure is the third, perhaps the fourth, church on the site. Consecrated by Franciscans, it was begun in 1783 and completed in 1797. One of the finest Spanish Colonial churches in the country, it is a synthesis of Baroque design and the desert materials from which it was built by Papago Indian laborers supervised by Spanish-American master craftsmen.