Technical Abstract: The Reynolds Creek Experimental Watershed has been in operation as an ARS outdoor-hydrology laboratory since 1960. The 239 km2 watershed in southwestern Idaho ranges from Wyoming big sage communities at 1100-m elevation to Douglas-fir forests at 2240-m. Approximately 1/3 of the watershed is in the mountain-sage precipitation and elevation zone with a historical fire cycle of 20-25 years. The last significant wildfire in the watershed occurred in the mid 1930’s. In 2002, NWRC initiated a cooperative research program to re-introduce fire to this ecosystem, and to study landscape-scale impacts on soil, vegetation, water and livestock resources. As ARS does not own any land at the watershed, this project is inherently collaborative as 23% of the land is in private ownership, and 77% is managed by BLM and the state of Idaho. NWRC has successfully completed two prescribed fires in this program in 2002 and 2004 and will be conducting a third fire in 2007. In the future, this project will continue to implement research and management burns at the watershed, on the scale of 200 to 400 ha, every second or third year. Private-land collaborators are allowing ARS to conduct research on their land and to monitor livestock distribution. BLM is working with ARS to develop the necessary NEPA documentation and burn plans, and manages implementation for all prescribed fires. NWRC scientists and their research cooperators have investigated pre and post-fire soil erosion with rainfall simulation, and monitored soil water and soil-water recharge, vegetation change, pre and post-fire grazing utilization, and the efficacy of prescribed fire for both fuels reduction and juniper control. Future collaborations in these and other research areas are both possible and desirable as the infrastructure is already in place for detailed hydrologic and meteorologic monitoring.