This point shapefile represents all air monitoring stations active in California from 2001 until 2003. The data within the shapefile was obtained from the Air Resources Board's Ambient Air Quality Data Summaries (ADAM) database. Developed for the California Air Resources Board (ARB) GIS data library. Teale Data Center GIS Lab. California Air Resources Board. (2013). Air Monitoring Stations: California, 2001-2003. California Air Resources Board. Available at: http://purl.stanford.edu/zv296hf8888. ADAM is the official database that stores regulatory air quality data for ARB. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.