Unless manifested by clearly recognizable archaeological phenomena (e.g., features, houses), site structure complexity often receives minimal attention. Yet, as this research shows, analysis of even low-density sites without features can yield evidence useful in defining site structure complexity. The 23 sites analyzed in this study ranged from small, single-use locations to large, complex base camps. Intensive analysis of artifact distributions, post-depositional processes and chronological data from these sites revealed definable site structure patterns. Comparison of these patterns to ethnoarchaeologically derived models yielded useful inferences about site reuse and the intensity and duration of occupation.