This part conclusion presents some closing thoughts on the key concepts discussed in the preceding chapters. The part examines, trading knit inhabitants of the Serrana, Pueblo, and Desert provinces together with those of western Mesoamerica. It discusses the impact of 1634-1636 epidemic disease mortality, called smallpox in contemporary documents but diagnosable as scarlet fever. The part focuses on chronological and related questions. Andres Perez de Ribas' reported cultural information that helps to increase chronological accuracy. Improving chronological precision is the key to interpreting correctly both local and regional events in Mexico's Old Northwest, just as it has proven to be in the lower Mississippi River Valley and the Appalachian Southeast. The known chronology of pandemic disease mortality, documented post-1600 redoubt-storehouse use and agave cultivation, plus customary archaeological inference from trade ceramics, are mutually consistent in dating "Classic Hohokam" termination to 1650.