"Large Scale" USGS 1:24,000 (24K) Digital Elevation Models (which correspond to 7.5 minute topographic quadrangle maps that cover about 6.3 x 8.7 miles) are available at 10 and 30 meter resolution. 30-meter data sets are available for the entire US. Parts of the country have both 10 and 30 meter data (also known as 1/3-arc second and 1-arc second data, respectively).

Even with JPEG compression, the difference between the two resolutions is obvious in the images above. They show blufflands along the Mississippi River in western Wisconsin. These DEMs are displayed in Global Mapper at about 25% zoom with hill shading turned on.

MapMart features an excellent map-based DEM locator showing where 10-meter DEMs are available. See Links for more information and sources.

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