The calendar was created for the 250th anniversary of the establishment of Presidio San Agustín del Tucson. This anniversary acknowledges the numerous and diverse communities that have contributed to the establishment of Tucson and the Sonoran region, many of which existed prior to the existence of the Presidio.

This significant anniversary in 2025 presents an opportunity to reflect on the intersection of hope, human endeavor, and the political intent of those whose aspirations were focused on establishing a new frontier and those whose lives were intertwined with the seasonal rhythms of the land. In retrospect, the founding of Presidio San Agustín del Tucson defined the trajectory of Tucson and the surrounding region. How do Tucson and the surrounding region continue to be shaped by this defining event?

This calendar was initiated in partnership between the Tucson-Pima County Historical Commission, the Arizona Historical Society, Los Descendientes, the Presidio Museum, the Southern Arizona Transportation Museum, and Vail Preservation Society. Proposals submitted to the calendar are reviewed by a panel made up of representatives from the calendar partners to ensure event criteria are met.