With National Science Foundation support Dr. Don Rice and his colleagues will conduct three field seasons of archaeological research in the Peten region of Guatemala. This research builds on a previously NSF supported project. The goal of the work is to understand what happened to Mayan cultures after the collapse of the `Classical Maya.` Archaeological evidence clearly demonstrates the degree of social complexity which was achieved at the height of Mayan development. Priest emperors ruled over large areas of lowland Middle America. A writing system was devised and the importance of monumental architecture is demonstrated by temple mounds which survive to present times. Both archaeological and textual data indicate that large numbers of people were integrated into single political units and that traditional agricultural techniques served to provide adequate food in a difficult lowland tropical environment. In approximately the 9th century AD however this classic Mayan society `collapsed` and the reasons for this are poorly known. DR Rice and his colleagues have focused on the time interval between the 9th and 17th centuries AD, when Europeans conquered this area. They have worked from early Spanish texts which described, and located - in a general way - major Mayan towns. Through on the ground survey they have located many of these and conducted trial excavations. This information has provided the framework for the current major excavation project which will allow the Mayan `decline` to be traced over a ca. 800 year interval. Drs. Rice, Rice and colleagues will excavate portions of 41 structures to obtain comparative data on site histories and functions of specific civic-ceremonial structure types. This project is important for several reasons. It will provide information on a little understood period of prehistory. The data it produces will be of interest to many archeologists and it will increase our understanding of how complex societies arise, and also decline.