Surficial geology of the Southwest Principal Aquifers (SWPA) study

These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This is a 100-meter cell resolution raster dataset consisting of 1:750,000-scale surficial geology for California and 1:500,000-scale for Nevada, and parts of Utah, Colorado, New Mexico, and Arizona. This data set was aggregated from a compilation of geologic maps of the Southwest Regional GAP Analysis Project (ReGAP) along with California geology and the very southern portion of Oregon and Idaho geology.