Suggested citation and version history for: Soller, D.R., Reheis, M.C., Garrity, C.P., and Van Sistine, D.R., 2009, Map database for surficial materials in the conterminous United States: U.S. Geological Survey Data Series 425, scale 1:5,000,000 [http://pubs.usgs.gov/ds/425/]. Version 1.0 July 29, 2011 - Added DS_425_MapUnitAndLineDescriptions.xls, .xlsx, and .ods to both .zip packages; these are spreadsheet files in different formats containing full descriptions of each map unit and parent map unit. September 11, 2009 - Provided standard USGS publications Web banner August 6, 2009 - The .mxd was saved with relative paths - Layer files were retargeted June 5, 2009 Initial release online at http://pubs.usgs.gov/ds/425/