http://pubs.usgs.gov/sim/3236/ Description of digital dataset files posted on this website: sim3236_readme.txt - this file sim3236_metadata.txt - FGDC compliant metadata. Each Geodatabase Feature Class also has its own metadata. topock_db.zip, expands to topock_db topock_db - Folder of files necessary to create an ArcMap Personal Geodatabase project. -- readme_topock_db.txt - Readme for topock_db -- topock.mdb - Personal Geodatabase -- topock.style - ArcMap style for symbolizing data -- o34114f4.tif - 1:24,000 DRG base topock_shape.zip, expands to topock_shape topock_shape - Folder of Feature Classes converted to shapefiles to facilitate use of the data in ArcMap and other applications. -- readme_topock_shape.txt - Readme for topock_shape -- shapefiles folder - Shapefiles -- topock.style - ArcMap style for symbolizing data -- o34114f4.tif - 1:24,000 DRG base