Several classes of data collected from Northern Black Mesa, Arizona, are used to identify seasonality among nineteenth- and twentieth-century Navajo sites. The data include informant accounts, site layout and composition, hogan doorway orientations, and terminal tree-ring condition from dendrochronological samples. While each class of data yields information regarding an aspect of site seasonality, analysis reveals that more than one kind of information is represented by the various data sources. Specifically, hogan doorway orientation and tree-ring seasonality provide mutually reinforcing evidence regarding season of site construction; other data relate to the season of site use. These results suggest refinements in the assessment of Navajo site seasonality, as well as providing more general information regarding the identification of site season in archaeological contexts. In addition, the recognition of the alternative seasonal information provided by the different kinds of data, suggests new approaches to analysis of mobility and activity patterns.