This layer is a georeferenced raster image displaying elevation data for Puerto Rico and the U.S. Virgin Islands, using an Albers Equal-Area Conic projection. The elevation data were derived from National Elevation Dataset (NED) data, and show the terrain at a resolution of 100 meters. The NED is a raster product assembled by the U.S. Geological Survey, designed to provide national elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections made in the NED assembly process minimize artifacts, permit edge matching, and fill sliver areas of missing data. The NED is updated on a bi-monthly basis. This data set was derived from NED data released in December, 2010. This layer is part of the 1997-2014 edition National Atlas of the United States.The 100-meter resolution elevation data were developed to portray the terrain of the United States at 1:1,000,000 scale. They are intended primarily for visual purposes. The original NED data should be used for conducting analysis and determining the most accurate elevation values. No responsibility is assumed by the National Atlas of the United States in the use of these data.