Despite great variability in archaeological and ethnographic material culture across North America, a handful of objects are ubiquitous in assemblages of different ages and geographies. These index objects are clues to ontological principles, such as animacy, that guide the interactions between Native Americans and the material world. The impact of relational ontologies on the formation of heterogeneous archaeological assemblages may be evaluated through analyses of index objects and contextual associations. To this effect, this article presents the outline of an assemblage-based relational taxonomy, where spatial, temporal, and formal dimensions are combined with object biographies, interactive roles, and social relations.