This polygon shapefile contains areas of relative liquefaction suceptability in Monterey County, California. A common type of ground failure associated with moderate and large earthquakes is liquefaction in which water-saturated fine-grained cohesionless sediments lose strength and may fail during strong ground shaking. Liquefaction susceptibility depends on the age and type of material, relative density of the material, and the depth to first (shallowest) water. Generally, younger sediments (especially latest Holocene that are less than 1,000 years old) such as loose fill, river channel, and flood plain deposits are more likely to liquefy than older Pleistocene terrace deposits. Relative liquefaction susceptibility was evaluated using a simplified version of the methodology developed for the Monterey Bay area by the USGS (Dupré and Tinsley, 1980; Dupré, 1990; Pike and others, 1994). The resulting data set shows that the areas of highest susceptibility include the Salinas, Carmel, San Antonio, and Peachtree Valleys. This layer is part of a collection describing Geology resources and constraints Monterey County, California.This map depicts the relative liquefaction susceptibility of sediments in Monterey County. The purpose of this map is to provide a comparison of relative liquefaction susceptibility for regional planning studies in Monterey County.