A mineral resource assessment for tungsten, a critical mineral commodity (see 'Related External Resources' section below) for the United States, was carried out by the U.S. Geological Survey (USGS) for a portion of the Great Basin region, in western Nevada and eastern California, between latitudes 36N and 42N and longitudes 116W and 120W. This study (Lederer and others, in review) integrates data from several sources, including geologic, geochemical, geophysical, remote sensing, watershed analysis, and mining with recently developed grade and tonnage models, expert estimates, and software tools and analyses to generate probabilistic estimates of undiscovered tungsten skarn resources. The assessment was conducted following the 3-part assessment methodology developed by Singer and Menzie (2010, see 'Related External Resources' section below), which involved the delineation of permissive tracts, as well as the evaluation of interdisciplinary data that were then presented to a panel of experts, who made estimations that were then analyzed using economic filters. These data are presented in several formats: a GIS geodatabase, shapefiles, and tabular (csv) data. Several layers or individual files are derived or contain data from U.S. Geological Survey (USGS) and other existing, published sources, mainly the USGS National Geochemical Database (NGDB), USGS Mineral Resources Data System (MRDS), and the National Uranium Resource Evaluation (NURE) databases.