The Bonneville Basin of Utah and Nevada is well known for cave sites having deep stratified archaeological records of human occupation spanning the last 12,000 years. These archaeological sites contain abundant well-preserved remains of plants that were mainstays of the diet of hunter-gatherers living in this arid region. With support from the National Science Foundation, Dr. David Rhode will carry out an analysis of plant remains from several archaeological sites in the Bonneville Basin. These collections include those already obtained from Danger Cave, Floating Island Cave, and Camelsback Cave, as well as new collections that will be made at Bonneville Estates Shelter, a cavern in eastern Nevada currently undergoing excavations and having a detailed archaeological sequence extending through the Holocene. Dr. Rhode will integrate data from these individual sites to create a regional record of changing plant-oriented subsistence strategies, and use this record to document how people changed their subsistence strategies in relation to long-term climate-driven changes in available plant resources. This research addresses four main research issues. First, archaeologists have long thought that the earliest inhabitants of the Bonneville Basin adopted small seeds as a dietary staple during the very early Holocene, much earlier than elsewhere in the intermountain West. This hypothesis will be re-examined using new evidence from Danger Cave and Bonneville Estates Shelter. Second, the regional record of plant use will show how foraging societies responded to widespread aridification and a decline of abundance of key food resources that began 8000 years ago, and which foreshadowed the development of foraging strategies that characterized many Great Basin native groups since then up until European contact. Third, a period of 'Neoglacial' climatic amelioration 4000-3000 years ago is expected to have strongly affected subsistence resource abundance and subsistence strategies, potentially resulting in dietary specialization toward high-return resources or, alternatively, retaining dietary generality but allowing a broad expansion of population. The regional record will allow tests among these alternatives of adaptive flexibility to resource abundance vs. adaptive integrity and population growth. Finally, cultural developments and subsistence shifts that occurred within the last 1500 years, including the expansion of Fremont farming societies and the subsequent return to foraging by Gosiute peoples, will allow a test of the tradeoffs between foraging and farming strategies and social integration in the context of regional environmental change in dryland environments. The record of prehistoric plant use developed for the Bonneville Basin will rank among the longest and most detailed available from North America and as good as any such sequence known worldwide. It will be compared with an equally well-dated and detailed paleoenvironmental record, to address important issues of regional prehistory and of adaptations of foraging societies to changing climates and resource distributions in drylands. Dr. Rhode will train undergraduate and graduate students, as well as interested members of local archaeological groups, in paleoethnobotanical techniques, and the research will be used to develop public displays at Utah's Danger Cave State Park, enhancing greater public enjoyment and appreciation of the value of archaeological resources in understanding of our past.