The U.S. Geological Survey Earth Resources Observation and Science Center Topographic Science Project has developed elevation-derived watershed basins and characteristics for major rivers of the conterminous United States. Watershed basins are delineated upstream from the mouth of major rivers by using the hydrologic connectivity of the Elevation Derivatives for National Applications (EDNA) seamless database. Watershed characteristics are quantified by integrating ancillary geospatial datasets, including land cover, population, slope, and topography, with elevation-derived watershed boundaries. The results are published in an online EDNA Watershed Atlas at http://edna.usgs.gov/watersheds. The atlas serves as a framework for evaluating and analyzing the physical, biological, and anthropogenic status of watersheds.