GIS - California

Lake Tahoe Data Clearinghouse
This site is maintained by the USGS along with other partners. This site provides many maps of the Tahoe area along with orthophotos and other downloadable maps. The maps can be downloaded in TIFF format along with a world file so the images can be opened directly into ArcView.

California Geographical Survey
Maintained by the Department of Geography at CSU-Northridge, this site provides a variety of datasets and maps. Included are census data archive, digital map bases, and an electronic map library.

California Wetlands Information System (CWIS)
As part of the California Environmental Resources Evaluation System, CWIS has compiled comprehensive wetlands information. This site allows you to view maps of wetlands in various locations.

USGS Geologic Mapping in California
The U.S. Geological Survey and its partners conduct geologic mapping in many parts of California. This site provides links to mapping projects concerned with environmental problems. Many of the maps can be downloaded in pdf format.

Access USGS for the San Francisco Bay Area
This site is maintained by the USGS and provides links to mapping projects in the SF Bay Area. The mapping projects are mostly environmental in nature. Many of the maps can be downloaded for use in ArcView.

Statewide Database
The Statewide Database (SWDB) is the redistricting database for the state of California.  Compiled from census data, resources from this site are available "free of charge to anyone interested in the political and demographic make-up of the State of California."

SANDAG: San Diego Association of Governments GIS
This site provides geographical maps, data, and projects in the San Diego area and surrounding region. Free downloadable GIS datasets are available, as well as interactive mapping and statistical tables.

Statewide Data Index
The California Spatial Information Library is providing statewide datasets formerly distributed by the Teale Data Center. Downloadable datasets include administrative districts, political districts, water districts, infrastructure, etc.

Sacramento Area Council of Governments Mapping Center
SACOG is the Sacramento Area Council of Governments and this site contains a variety of GIS data files available for downloading.

Mojave Desert Ecosystem Program

Napa County GIS

US Fish & Wildlife Service – California Spatial Data Sets

USGS Seafloor Mapping

Natural Resources Conservation Service – Soil Data Mart

USDA Forest Service – Pacific Southwest GIS Clearinghouse