This paper presents a synthesis of recent work in the Caves Branch River Valley, which has focused on the many cave and rockshelter ritual sites and the core of the monumental center Deep Valley. These results are supplemented by data generated from prior investigations in the that allows us to establish that small stable communities in the valley beginning in the Middle- Late Formative period and continuing through the Late Classic period were the norm. This pattern was abruptly broken in the Late-Terminal Classic with a brief period of annexation of the valley into a broader political and economic sphere. While thelimited settlement data seem to point to increased population sizes during the late period, the main body of evidence comes fromvariations in the ritual use of caves and rock shelters, which increases dramatically and shows evidence for changes that can beinterpreted as demonstrating increased social complexity within local populations and as reflecting less provincialism. Inaddition, the hastily constructed site of Deep Valley clearly reveals the late presence of some type of centralized administration.Taken together, these data suggest a late and significant influx of migrants into the valley, followed by a sudden depopulationconcurrent with similar abandonment’s at nearby centers