This polygon shapefile depicts boundaries for vernal pool regions throughout California.This coverage is a polygon layer of vernal pool complexes in California. In 1995, Dr. Robert F. Holland identified the complexes on aerial photos (the most recent available for each county) and traced the polygons onto USGS 7.5' quads from which they were digitized. Vernal pool complexes were then given a density rating. The coverage was refined in June of 1998, with SPOT Imagery and recent U2 (low-flying aircraft) photography. The layer does not contain delineations of individual vernal pools and was not intended for use in wetland delineations. This coverage allows for assessment of vernal pool areas in California state-wide.