The database represents delineations of aspen stands, where aspen assessment data was gathered. Aspen assessment information corresponding to this polygon layer can be found in the layer: ADP_POINT. Data collection occurred in the Lake Tahoe Basin Management Unit (Placer and Eldorado Counties); Alturas Field Office-BLM (Modoc County); California Tahoe Conservancy (Placer and Eldorado Counties), the Stanislaus National Forest (Tuolumne County); Humboldt-Toiyabe National Forest(Alpine County); and Tahoe National Forest (Nevada and Sierra Counties); and the California Department of Fish and Game (Modoc County). This is a multi-agency contributed dataset gathered by the agencies listed above during the summers of 2001-2005. Assessment data and GIS delineations were collected using a standardized protocol developed by members of the Aspen Delineation Project, a cooperative project of the US Forest Service, the Bureau of Land Management and the California Department of Fish and Game. Surveying was completed by foot surveys of watersheds surveyed. This is the current completed data set for aspen distribution of land administered by these agencies. Data captures location of aspen stands and vegetative characteristics of the aspen stand, and if browsing of the aspen was present or absent. Also associated with this database is a point layer (ADP_POINT) containing aspen stands delineated in conjunction with the aspen assessment information. Data Compilation: The Aspen Delineation Project (ADP) is a collaborative effort of the U.S. Forest Service's Pacific Southwest Region, the California Department of Fish and Games Resource Assessment Program, and the California Office of Bureau of Land Management. Principal Investigator for ADP is David Burton; visit: www.aspensite.org for more information regarding the ADP. The Department of Fish and Games, Resource Assessment Program compiled this information from the collaborating agencies and other researchers, and formatted the data into a common database for the purpose of facilitating access to data related to the conservation of Quaking Aspen in California. This information portal falls within the ADP goals to help agencies and land managers identify, map, treat, and monitor aspen habitats. This dataset is a portion of a master database compiled during a year long effort in 2005 to pull together current GIS layers and maps depicting Aspen communities in California.