"Revised August 1990 1004588-47." "Source: Digitized from SCS thematic 1003272 dated June 1980. Map compiled using automated map construction with the FOCAS equipment. National Cartographic Center, Fort Worth, Texas 1990." "Figure 10." Indexed. Available also through the Library of Congress Web site as a raster image.
National Cartographic Center (U.S.); United States. Soil Conservation Service
1990
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