Below: Index map showing available quadrangles of the current California Regional Geologic Map series. Click or tap the image to see a larger version.
About CGS Geologic Mapping
The California Geological Survey prepares geologic maps in cooperation with the U.S. Geological Survey’s National Cooperative Geologic Mapping Program. Geologic mapping priorities are established by the California State Geologist and the California Geologic Mapping Advisory Committee.
We begin with 7.5 minute quadrangles at 1:24,000 scale. We compile those into 30-by-60 minute quadrangles at 1:100,000 scale, which retain all of the detail of the 7.5 minute quadrangles. When an entire 30-by-60 minute quadrangle is compiled, reviewed, and approved, we release it into our official
California Regional Geologic Map series.
The maps on this page are considered preliminary. We make digital versions of preliminary maps available so you may have timely access to the information. You can download them using the links provided below.
Please note, preliminary maps are available as PDF files only. Printed versions are not available.
For data requests and technical comments related to Geologic Mapping, please contact Janis Hernandez.
Preliminary 30-by-60 Minute Quadrangles (1:100,000 scale)
Preliminary 7.5 Minute Quadrangles (1:24,000 scale)
Select a region from the choices below to jump to a list of that region's 7.5 minute quadrangles.
North Coast Region
Northern San Francisco Bay Region
Note: The 7.5 minute quadrangles within the Napa 30-by-60 minute quadrangle (outlined in red below) have been updated and are superseded by the Preliminary Geologic Map of the Napa-Bodega Bay 30-by-60 minute quadrangle (Wagner and Gutierrez, 2017).
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Calistoga, 2013 (4.1 MB)
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Camp Meeker, 2009 (7.2 MB)
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Capell Valley, 2006 (7.7 MB)
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Cordelia, 1998 (3.6 MB)
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Cotati, 2003 (4.2 MB)
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Cuttings Wharf, 2002 (3.0 MB)
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Fairfield North, 2006 (6.2 MB)
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Fairfield South, 1998 (2.7 MB)
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Geyserville, 2012 (3.6 MB)
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Glen Ellen, 2003 (5.4 MB)
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Healdsburg, 2011 (8.2 MB)
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Jimtown, 2010 (9.0 MB)
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Kenwood, 2007 (2.4 MB)
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Mt. George, 2004 (3.4 MB)
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Mt. Vaca, 2007 (2.8 MB)
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Napa, 2004 (3.8 MB)
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Novato, 2002 (2.3 MB)
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Petaluma, 2002 (2.5 MB)
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Petaluma River, 2002 (1.6 MB)
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Rutherford, 2005 (11 MB)
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Sears Point, 2002 (2.0 MB)
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Sebastopol, 2008 (3.7 MB)
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Sonoma, 2004 (3.7 MB)
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Two Rock, 2003 (4.0 MB)
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Valley Ford, 2008 (4.6 MB)
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Yountville, 2005 (10 MB)
Lancaster-Victorville Region
San Luis Obispo Region
Note: The 7.5 minute quadrangles shown below have been updated and are superseded by the Preliminary Geologic Map of the West Half of the San Luis Obispo 30-by-60 minute quadrangle (Wiegers, 2018; un-simplified digital database available upon request).
Santa Barbara-Los Angeles Region
Note: The 7.5 minute quadrangles within the Los Angeles 30-by-60 minute quadrangle (outlined in red below) have been updated and are superseded by the Preliminary Geologic Map of the Los Angeles 30-by-60 minute quadrangle (Campbell, et al, 2014).
Oceanside-San Diego Region
Note: The 7.5 minute quadrangles within the Oceanside 30-by-60 minute quadrangle (outlined in red below) have been updated and are superseded by the Geologic Map of the Oceanside 30-by-60 minute quadrangle (Kennedy and Tan, 2007).
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Aguanga, 2014 (5.2 MB)
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Bonsall, 2000 (3.2 MB)
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Boucher Hill, 2014 (8.9 MB)
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Dana Point, 1999 (2.3 MB)
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El Cajon, 2002 (2.2 MB)
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Escondido, 1999 (2.7 MB)
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Fallbrook, 2000 (4.7 MB)
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Jamul Mountains, 2002 (2.1 MB)
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Las Pulgas Canyon, 2001 (3.7 MB)
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Margarita Peak, 2001 (5 MB)
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Morro Hill, 2001 (3 MB)
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Otay Mesa, 2002 (1.2 MB)
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Pala, 2000 (4 MB)
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Pechanga, 2000 (4.2 MB)
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Ramona, 2007 (4.0 MB)
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San Clemente, 1999 (5.2 MB)
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San Onofre Bluff, 1999 (1.9 MB)
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San Pasqual, 2007 (2.5 MB)
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San Vicente Reservoir, 2002 (1.7 MB)
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Temecula, 2000 (4.8 MB)
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Vail Lake, 2014 (6.2 MB)
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Valley Center, 1999 (3.3 MB)
Web page by:
California Regional Geologic and Landslide Mapping Program
