With support from the high risk program of the Archaeology Program of the National Science Foundation, Dr. Joyce White and an international team of colleagues will conduct the first fieldwork season in Laos of the Middle Mekong Archaeological Project (MMAP). The team brings together U.S., British, Lao, and Thai archaeologists and geographers who will undertake a reconnaissance survey of three left bank tributaries of the Mekong River in Luang Prabang province. The objective is to find sites likely dating to the middle Holocene, roughly 6000-2000 BC calibrated, in order to begin acquiring data to test alternative models for the appearance of agriculture in mainland Southeast Asia. The timing, mechanisms, and ramifications of the emergence of early agriculture in Southeast Asia are hotly debated by archaeologists studying Asian prehistory. Multi-disciplinary arguments over the roles of migration from northern latitudes as opposed to indigenous developments engage disciplines ranging from historical linguistics, palaeopalynology, human, animal, and crop genetics, as well as traditional archaeology. MMAP seeks to redress the fact that existing archaeological data from the middle Holocene in mainland Southeast Asia, during which the transition from hunting and gathering to agriculture in this region occurred, are currently too poor in quantity and quality to scientifically evaluate alternative scenarios under discussion. Determination of the timing and nature of the development of early agriculture in Southeast Asia has implications not only for the culture history of one region, but also for the validity of the proposal that modern day global distributions of languages and populations represent expansions from a few regions where some scholars propose that agriculture originated. Scholars with this "Gardens of Eden" view see Southeast Asian languages, populations, and agriculture originating from the Yangtze basin where the earliest domesticated rice has been found. However, existing evidence from demography, plant genetics, and human biology in mainland Southeast Asia may not support the proposal. Knowing if the original agricultural societies in Southeast Asia came from an extraregional expansion driven by the development of rice cultivation, autochthonous developments of plant cultivation perhaps of multiple crops, or some combination of processes is important not just for evaluation of the Gardens of Eden proposal. Knowing if a rice-focused cropping system as opposed to a multi-species horticultural cropping system characterized Southeast Asia's original agricultural regime is fundamental to understanding the region's distinctive social, economic, political, and environmental trajectories. Geographic factors indicate that there is no better location in all of Southeast Asia to seek evidence for changes in middle Holocene subsistence regimes than Luang Prabang province. Luang Prabang is upstream from Ban Chiang cultural tradition sites in northeast Thailand where the earliest agricultural societies so far identified in the middle Mekong basin lie. Luang Prabang province is also on the western side of a divide whose eastern side in Vietnam witnessed subsistence changes during the middle Holocene that the Vietnamese claim involved exploitation of domesticated livestock. The MMAP exploratory survey will provide data to help plan future archaeological investigation in Laos involving excavation and intensive survey. This research will impact society and knowledge at a variety of levels. Laos is virtually an archaeological terra incognita, yet encompasses the inner core of mainland Southeast Asia. Little research has been done since the colonial period before World War II because of ongoing regional conflicts and the country's political isolation since the Vietnam War. Thus Laos holds a keystone for knowledge of human past for a major part of Asia as questions have arisen from research in neighboring countries such as Thailand during the past 30 years. Laos is a very poor country, which only recently received normalized trade status with the United States. Thus joint projects between the Lao Department of Museums and Archaeology (DOMA) and US universities can have major repercussions for training of local archaeologists, development of infrastructure for archaeological research and museology, and transfer of information technology and archaeological method, theory, and knowledge to local cultural resource managers.