Notes:

This map layer includes sand and gravel operations in the United States. These data were obtained from information reported voluntarily to the USGS by the aggregate producing companies. The data represent commodities covered by the Minerals Information Team (MIT) of the U.S. Geological Survey, and the operations are those considered active in 2002 with production greater than 50,000 tons, which are non-government, non-portable, and surveyed by the MIT. This is a replacement for the January 2001 map layer.The data is legacy and not expected to be updated. It is being provided as the best available until Mineral Resources identifies an alternative data source.