The CGS published the first six maps of this series at 1:250,000 scale. After 1992, we began producing more detailed, larger scale maps (1:100,000 and 1:24,000 scales). To date, there are more than 100 new or updated geologic maps in the current RGM series: ten are officially Published, while the remainder are still considered Preliminary (see the sidebar below regarding Preliminary Regional Geologic Maps).
Sidebar: Preliminary Regional Geologic Maps
The California Geological Survey has several new and updated geologic maps that are considered Preliminary, awaiting official publication. We make digital versions of these Preliminary maps available before publication so you may have timely access to the information. Follow this link to explore our collection of Preliminary Regional Geologic Maps.
You can download Published maps of the current Regional Geologic Map series using the links provided below. Printed versions can be purchased from the CGS Publications sales desk.
The Geologic Atlas of California was published between 1958 and 1969. Although more recent and more detailed mapping is available in many areas
(see Current Regional Geologic Map Series, above), this set of maps is still the most detailed interpretation available for the entire state. It provides a complete, consistent view of the geology of the state, prepared at 1:250,000 scale. The Geologic Atlas uses a single set of rock units defined by geologic time, rather than geologic formations defined by time and lithology. This allows a simplified, uniform depiction of geologic units.
The following index map and list provide the areas covered by the individual sheets of the Geologic Atlas. You can download maps from the Geologic Atlas of California using the links provided in the list.
CGS prepared these editions of the Geologic Map of California and the Fault Activity Map of California in recognition of the California Geological Survey’s 150th Anniversary.