The USGS National Elevation Dataset (NED) has been developed by merging the highest resolution, best-quality elevation data available across the United States into a seamless raster format. NED is the result of the maturation of the USGS effort to provide 1:24,000-scale digital elevation model (DEM) data for the conterminous United States, and 1:63,360-scale DEM data for Alaska. The shaded relief display is derived from NED using a hill-shade technique. NED data are available nationally at grid spacings of 1 arc-second (approximately 30 meters) for the conterminous United States, and at 1/3 and 1/9 arc-seconds (approximately 10 meters and 3 meters, respectively) for parts of the U.S. This metadata pertains to the Web Map Service (WMS) used for visualization of medium scale shaded relief in The National Map viewer.View Full FGDC Metadata from geo.data.gov