This poygon shapefile contains a geologic model of Monterey County, California. For geologic and seismic hazard evaluation, the most important factor is the geologic model. In this study, the geologic model is a digital compilation of stratigraphic formations and faults in Monterey County. T.W. Dibblee, Jr. mapped most of the geology in Monterey County for the U.S. Geological Survey in the 1960s and 1970s. Other major contributors of mapping include J.C. Tinsley, III, W.R. Dupré, V.M. Seiders, D.C. Ross, J.C. Clark, and C.A. Hall. To provide a logical framework for the many geologic units in Monterey County, T.W. Dibblee, Jr. prepared a countywide correlation of map units, with emphasis on the Tertiary and Cretaceous age sedimentary rocks. Cretaceous plutonic and metamorphic rocks follow the nomenclature of Ross (1972, 1976). Quaternary deposits are classified based on the work of Tinsley and Dupré. This data set presents a unified, seamless geologic coverage for the seventy-nine 1:24,000 scale quadrangles that cover Monterey County. This layer is part of a collection describing Geology resources and constraints Monterey County, California. The purpose of this map is to provide a seamless, regionally consistent geologic database for regional planning studies in Monterey County. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.