[en] This work develops a comprehensive set of watershed definitions for the entire Oak Ridge Reservation and surrounding area. A stream-ordering system is defined based upon the method proposed by Strahler (1952) and using 1:24,000 scale US Geological Survey (USGS) topographic maps and the locally standard S-16A Map (USGS 1987) as sources for topographic contours and locations of streams as recommended by the Natural Resources Conservation Service (NRCS 1995). For each ordered stream, a contributing watershed or catchment area is delineated and digitized into a geographic information system (GIS), generating over 900 watershed polygons of various orders. This new dataset complements a growing database of georeferenced environmental and cultural data which exist for the Oak Ridge area and are routinely used for socioeconomic and environmental analyses. Because these watersheds are now available in a GIS format, they may be used in a variety of hydrologic analyses, including rainfall/runoff modeling, development of geomorphological parameters, and the modeling of contaminant transport in surface waters. An understanding of the relationships of watersheds to sources of contamination and to administrative and political boundaries is also essential in land use planning and the organization of environmental restoration and waste management activities