A long-running debate in archaeology is the analytical priority given to local vs. interregional-scale factors in the origins of complex societies. These alternate approaches have often pitted local-scale, environmentally determined models against the large-scale, sociopolitical demands of ancient cities and states. In the archaeology of Oaxaca, Mexico, these distinctions are apparent in efforts to model the impact of Monte Albán on the development of complexity outside the Valley of Oaxaca. Huamelulpan, located in the western Mixteca Alta, Oaxaca, was one of Mesoamerica's first urban centers. But despite several decades of intermittent work, the site had never been surveyed, and nearly nothing was known of the surrounding region. A systematic archaeological survey of Huamelulpan and its environs studied the urban transition from a regional perspective. Huamelulpan's urbanization was strongly correlated with the formation of a state-level polity. Interaction with Monte Albán occasioned these developments, albeit in ways more indirect than colonization or conquest. An approach to culture change is outlined that uses archaeological survey data to shift the scale of analysis between local, regional, and interregional levels to interpret the transition to city and state in Oaxaca's Huamelulpan Valley.