This account of the drama in time that is Tucson begins not with the founding of the Presidio San Agustín on August 20, 1775, but with the emergence of Sentinel Peak in geologic deep time. It ends -- "To be continued" -- in 2014. It spans the periods of precontact with Europeans, Spanish colonization, Mexican nationhood, the territorial West, early and Depression era statehood, and the development of metropolitan Tucson after World War II. It offers not one definitive historical account but a collection of stories in which threads appear that may disappear beneath the surface for a while and reappear later, like some desert streams. It leaves spaces for, and invites the stories of, its readers.