DEM Data Sources

General Description
Digital Elevation Model (DEM) is the terminology adopted by the USGS to describe terrain elevation data sets in a digital raster form. The 7.5-minute DEM (30- by 30-m data spacing, cast on a Universal Transverse Mercator (UTM) projection) provides coverage in 7.5- by 7.5-minute blocks. Each product provides the same coverage as a standard USGS 7.5-minute quadrangle without over edge. Coverage is for the contiguous United States, Hawaii, and Puerto Rico. This is a data-set level implementation of the Federal Geographic Data Committee's Content Standards for Digital Geospatial Metadata.
Copyright © 1998, Idaho Geospatial Data Center, University of Idaho
http://geolibrary.uidaho.edu/GeoLib/tutorial/dem_background.htm

Data Locations/Descriptions