1972. Geological Survey (U.S.). This map layer portrays the 2000 state and county boundaries of the United States, Puerto Rico, and the U.S. Virgin Islands. The map layer was crea... U.S. Geological Survey.
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1972. American Geological Institute, Geological Survey (U.S.), and Environmental Systems Research Institute (Redlands, Calif.). This datalayer is a point coverage representing metallic and non-metallic mineral resources worldwide. This data was derived from the Mineral Resou... American Geological Institute.