This ethnohistory examines Indian life in the twenty-one missions Franciscans established in Alta California. In describing how the missions functioned between 1769 and 1848, the authors draw on previously unused sources to analyze change and continuity in Indian material culture and religious practices. The twin goals of Franciscans were to mold Indians into a work force that would produce surplus grain for military garrisons and to regulate their moral conduct and religious practices. The authors use production records to show the missions were quite effective in serving the economic goals. Also carefully assessed are the efforts to transform the culture and world view of Indians by delineating how they coped, their history of disease and death, and their efforts at resistance.