This study focuses on the altars of the major annual Hopi ceremonials which display ritual objects, the possession and use of which give religious and secular power. With the importance of such objects in mind, an iconographic study of Hopi religion is particularly illuminating. This study aims to demonstrate how to view Hopi altars and is supplemented by a theory of the mechanics of efficacy in the Hopi altar context. The text provides a general introduction to Hopi religious practice and distinguishes three levels of information: 1) the calendrical and ritual contexts of Hopi altars, 2) the functions of these altars within those contexts, and 3) the iconography and iconology of the altars, understood here in a literal sense as the study of the forms and structures of the altars on the one hand and the study of the implicit and explicit symbology of the altars on the other. The book provides keys to understanding through exemplification and typology, and is meant to be of particular use to museums and research libraries.