Technical Abstract: Research and assessments at a watershed scale require a multitude of data that are often available from diverse locations. When assessments are conducted across multiple watersheds, data compilation and management is even more complex. As part of the multi-agency Conservation Effects Assessment Project, ARS has estabilshed multiple location Watershed Assessment Studies. As part of that effort, a multi-location team has developed a web-based data system named STEWARDS: Sustaining the Earth's Watersheds, Agricultural Research Data System to organize and document soil, water, climate, land-managment, and socio-economic data from fourteen watersheds and provide data search, visualization, and downloads to users. STEWARDS consists of four components: databases (measured data, metadata, GIS layers), servers, clients (users), and research watersheds (data sources). The alpha version of STEWARDS includes data from El Reno, OK; Ames, IA; and Columbia, MO. While the alpha system is under testing within the CEAP research team, additional watersheds are preparing to upload data into STEWARDS prior to public release. Case studies using the alpha system illustrate the functionalities of STEWARDS for data visualization and downloading land-management data for conservation practice assessment using SWAT model. Once the public version of STEWARDS is released, the visiblity and impact of ARS watershed reserach investments will be greatly imporved.