United States. Soil Conservation ServiceGeographic coverage by soil conservation district. "Interpretations derived from soil map constructed ... by Cartographic Division, Soil Conservation Service, USDA ... of Puerto Rico."" ""Base source: USGS base map 1:100,000 dated 1979." Includes location map and notes.17 maps : color ; 92 x 123 cm or smallerScale 1:50,000JPEGeng.United States. Soil Conservation ServicePublicImportant Farmlands...Puerto RicoMapsPuerto Rico--United States Puerto RicoPuerto Rico1981Pennsylvania State University