This polygon shapefile depicts hydrologic unit watersheds for the nine county San Francisco Bay Area Region, California. Hydrologic Units are those ranging in size from 672-12,734 square miles or 430,000-8,149,999 acres (Myers & Peltz-Lewis, 2004). This data was derived from the California Watershed Map (CalWater version 2.2), a set of standardized watershed boundaries meeting standardized delineation criteria. The hierarchy of watershed designations consists of six levels of increasing specificity: Hydrologic Region (HR), Hydrologic Unit (HU), Hydrologic Area (HA), Hydrologic Sub Area (HSA), Super Planning Watershed (SPWS), and Planning Watershed (PWS). The primary purpose of CalWater is the assignment of a single, unique code to a specific watershed polygon. Watersheds are useful for many aspects of the Project, including development of watershed integrity analysis. These data were critical for the Fish and Riparian Focus Team portion of the Project. This dataset was developed/compiled for use in the San Francisco Bay Area Upland Habitat Goals Project, a Project used to identify a Conservation Lands Network (CLN) for biodiversity preservation to inform conservation investments and lasting cooperative conservation partnerships. The Conservation Lands Network GIS Database is the primary output of the Project. The data depicts the spatially explicit CLN that is recommended for the nine county San Francisco Bay Area Region, California.