With support from the National Science Foundation, Dr. Ronald Towner, students, and volunteers, will conduct two seasons of archaeological tree-ring sampling, analysis, and interpretation of a large set of pristine Early Navajo archaeological sites in the Navajo homeland of Dinetah in northwestern New Mexico. This project will: (1) more than double the number of tree-ring samples collected from Gobernador Phase (AD 1650-1775) Navajo sites with a concomitant increase in the number of absolute dates, (2) delineate the temporal and spatial aspects of three areas of known high-density 18th century Navajo occupation and compare them to existing data from three previous projects, (3) synthesize all tree-ring dated Navajo sites in Dinetah, (4) compare and contrast Early Navajo settlement patterns with extant tree-ring based reconstructions of climate, and (5) build new models of Early Navajo demography and social organization at the household, residence group, mid-level, community, and possibly tribal level. The resulting data and interpretations will significantly aid archaeologists, anthropologists, historians, and geographers in understanding the occupation of Dinetah by Early Navajo social groups, the broader population dynamics of the early historical period in the northern Southwest, and the relationships between human behavioral variability, climate variability, and sociopolitical change. Navajo social organization has been the subject of extensive and intensive anthropological research for decades, but the vast majority of such research has concentrated on Reservation-era (post-1868) groups west of the Chuska Mountains. Early Navajo archaeology in Dinetah provides an opportunity to examine the social organization of pre-Reservation Navajo groups who were not committed to pastoralism, but instead practiced a very mixed economy during times of severe climatic and social stress. This project will use tree-ring, archaeological, anthropological, historical, and extant oral history data to illuminate aspects of Gobernador phase Navajo settlement prior to the adoption of a pastoral lifeway and will significantly enhance our understanding of Early Navajo social organization prior to the Navajo transformation to pastoralism. The project will result in significant advances in understanding Early Navajo cultural dynamics and social organization; it will illuminate important aspects of Early Navajo demography, and enhance anthropological theories of mid-level social organization. This project will have significant impacts beyond the Dinetah Navajo and archaeology. It will make important contributions toward understanding how and under what conditions various forms of social organization developed in a pre-industrial, frontier-contact society. Models of such social formation processes will contribute to a broader understanding of human social organization during periods of demographic, climatic, and sociopolitical stress. The project will also contribute toward student training and development. It may also contribute to calibration other chronometric techniques, such as archaeomagnetism and thermoluminescence dating, and to refining ceramic seriation studies of protohistoric and early historic pottery types. It will refine models of Navajo wood use that may have implications for understanding the impacts of technological change on the exploitation of forest resources.