Canyon de Chelly and its major tributary, Canyon del Muerto, have been considered a Navajo "heartland" in the American Southwest since the 1700s. The canyons are usually referred to as a single social and economic community whose unique topographic features afforded an unusually dependable indigenous horticultural base. This paper describes important differences between the canyons in the history of Navajo land-use and settlement patterns. It is suggested that microregional differences can be linked with broader cultural processes and that both historicalnd ecological factors must be considered when interpreting such variation at whatever level it occurs.