The US Geological Survey Geographic (USGS) Data Download Web site contains a large selection of downloadable digital elevation models (DEM) in various formats. Visitors will find links to 1:250,000 Scale Digital Elevation Models, 1:24,000 Scale Digital Elevation Models, 30 Meter Resolution National Elevation Dataset, 1:2,000,000 Digital Line Graphs, 1:100,000 Scale Digital Line Graphs, 1:24,000 Scale Digital Line Graphs, 1:250,000 and 1:100,000 Scale Land Use Land Cover, National Land Cover Data, and National Hydrography Dataset. The site provides examples, status maps, user guides, and other information about each data set, making it a great overall resource for these helpful topographic models. [JAB]