Dr. Kolata and his colleagues will begin research at the prehistoric site of Tiwanaku in Northern Bolivia. For more than a millennium (ca. A.D. 100-1200), Tiwanaku was the paramount city of the Lake Titicaca basin which was, in turn, one of the great demographic centers of native Andean civilization. However, despite Tiwanaku's important position in the prehistory of the Andes - it is one of the early centers of state formation - little is known about its economic history and how it rose to prominence, governed an empire, and then declined. Dr. Kolata's research is designed to fill this gap. In past work Dr. Kolata has examined the agricultural system which sustained this large population. Now he will focus on the city proper. Rather than excavate monumental architecture, he will focus on domestic structures which will shed light on how the inhabitants subsisted and how they were organized. He plans to examine a series which extends from "commoner" to "elite" dwellings. Excavation of craft production areas should also provide insight into economic organization. Artifacts will be analyzed in the field, and Dr. Kolata will collaborate closely with Bolivian colleagues. This research is important for two reasons. First, it will shed light on a little understood aspect of South American prehistory. The Tiwanaku empire rose quickly and extended its influence rapidly over a wide area. This history is little understood. Second, it will increase our understanding of the more general question of how complex societies such as our own arise and are maintained.