"Base map prepared by the Geological Survey in cooperation with the Soil Conservation Service." Base map "Compiled from USGS 1:24 000-scale topographic maps dated 1969-1978." UTM grid. Includes text, notes, and location map. "July 1981 base 4-R-37210." Available also through the Library of Congress Web site as a raster image.
United States. Soil Conservation Service; Geological Survey (U.S.)
1981
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