CALIFORNIA GEOLOGICAL SURVEY
Welcome to the California Geological Survey Web Site!
In April 1860 the California Legislature established the Geological Survey of California that has evolved during its 150 years of service, and several name changes, into today’s modern California Geological Survey (CGS). Of course, the earliest history of CGS has its founding roots entwined with the discovery of gold in 1848.
CGS is dedicated to the fulfillment of its mission to provide scientific products and services about the state's geology, seismology and mineral resources that affect the health, safety, and business interests of the people of California.
CGS geoscientists, engineers and support staff take great pride in upholding the heritage of an organization that has a 150 year legacy of providing the highest quality of scientific and engineering products and services to the State of California.
Altiora Petimus (1860)
News & Events
- 2012 Golden Guardian Exercise
In conjunction with Golden Guardian 2012, the California Earthquake Clearinghouse is conducting a preparedness exercise.
Click here to learn more about this exercise.
- CGS Library Catalog now online!
CGS now offers the ability to search the entire CGS library catalog. Click here to begin your search!
- A New Way to Access CGS Natural Hazard Information
A collaborative web service called MyPlan has been established by the California Emergency Management Agency and the California Natural Resources Agency (CNRA) to provide a “one-stop shop” for local agency access to inter-active map information regarding natural hazards in California. Alongside contributions from Cal Fire and Water Resources, CGS provides information for earthquake and tsunami hazards. CGS worked closely with CNRA developers to ensure accurate representation of its hazard information, and will continue to provide more data offerings through this service. Ready access to these data allows for enhanced dissemination of agency products to support local land-use and development decisions, and facilitates preparation and updating of local hazard mitigation plans. The new site can be accessed at: http://hazardmitigation.calema.ca.gov/myplan CGS will continue to provide natural hazard information through its own website in addition to the new service.
- Thirteen proposed new and revised Preliminary Alquist-Priolo Earthquake Fault Zone maps Released March 7, 2012.
Areas covered include Alameda, Imperial, Riverside, San Diego, and Ventura counties. Click here to view or download the proposed new and revised maps
- National Tsunami Preparedness Week - March 25-31, 2012
For more information on California Tsunami preparedness, educational materials, and inundation maps, click here.
- CGS now has the entire collection of the California Geology magazine accessible in an online searchable database.
Click here to begin your search!
- Access Interactive Tsunami Maps using a Google Maps Interface
Click on the image to access the maps.
- CGS offers online access to Alquist-Priolo Earthquake Fault Zone Maps and GIS data.
Click here to view/download the maps 
- State Geologic Map and State Fault Activity Map!
- Click here to learn more about the History of Geologic Maps of California.
- Engineering Geologist Exam now available online
Click here to learn more about the exam and take the online test.
- Click here for more news!
RECENT RELEASES
- April 30, 2012 - Special Report 221
Triggered Surface Slips in Southern California Associated with the 2010 El Major-Cucapah, Baja California, Mexico, Earthquake
Click here to view the report.
- April 26, 2012 - Preliminary Seismic Hazard Zone Map for the Lick Observatory 7.5-minute quadrangle
Click here to view the maps.
- March 28, 2012 - Special Report 223
Mineral Land Classification of the Proposed Riddle Surface Mine Property Site, Stanislaus County, California - for Construction Aggregate.
Click here for the Release Statement.
- March 28, 2012 - Special Report 215
Update of Mineral Land Classification: Concrete Aggregate in the San Luis Obispo - Santa Barbara Production-Consumption Region, California.
Click here for the Release Statement.
- March 13, 2012 - New Map Release
Geologic maps of the Tehachapi and East Half of the Taft Quadrangles are now available online as part of CGS Special Report 217.
Click here to view/download the maps.
- January 6, 2012 - New 2012 CGS Calendar!
Visit the CGS Library and pick up your copy for $2 today! (Limited supplies on hand, walk-ins only)Click here to download your own calendar.
- December 30, 2011 - New Map Release - Landslide Inventory Maps
CGS has released maps for the Lick Observatory and Murrieta 7-5-Minute Quadrangles.
Click here for the Release Statement.Click here to go to the maps.
- CGS releases State Geologic Map and State Fault Activity Map.
Printed copies are now available for purchase.
Geologic Map Release Statement.
Fault Activity Map Release Statement.
- Click here for more recent releases!