This digital product contains detailed information about the surficial geology of the Northern Tucson Basin and the Tucson Mountains. The information comprises a GIS database and a visualization of the data as a default map layout. The map layout is included in an ArcView v3.2 project (.apr) file. This product is intended for use on a Windows 95, Windows NT, or higher platform, and an overview of the files distributed with this product is given in the file tree below. Arcview, or another GIS program capable of opening ESRI shapefiles and coverages, is required to use this product. The installation files for a simple ESRI viewing program, ArcExplorer, have been included with this product if the necessary GIS software is not available. The ArcExplorer program, however, does not take full advantage of the information available in this product.