University Library

Maps & Aerial Photos

How to Find Geologic Maps of California

Finding these maps is a two step process:
(For geologic maps outside California use National Geologic Map Database)

1. Find the names of the topographic maps for your area:

  • Find topographic map names using USGS MapFinder  
  • Navigate to your area and note the names for the 1:24,000 scale maps (aka 7.5’ maps)
  • You'll need these map names to locate them in the UCSC collections
  • 15’ historic maps of the Monterey Bay region (The 15’ map is in the center and names of 7.5’ maps are in smaller squares in brown type.)


2. Using this name, search for:

Geologic maps in the UCSC Library:

  • Go to  CruzCat (Maps & Atlases)
  • Enter a keyword search using the name of the topographic map along with “and geologic” (e.g. “Watsonville and geologic”).
  • Too few results? Enter the name of the topographic map alone.

USGS geologic maps (Our library has all the USGS report series)

Find USGS publications online

Most USGS publications are now available online:

  • Go the the USGS Publications Warehouse
    Click on advanced search in the middle of the screen.
  • Pull down the “Limit by” menu, and choose Report Series
  • An arrow will appear at the right end of the search box. When you click on it, you'll get a list of the USGS reports series. Select the one you want.  (try Bulletin)
  • In the search box at the top, fill in an author's name, a subject, or a title.
    • Sample author: Sweetkind
    • Sample subject: Loma Prieta
  • Results will be sorted by date, but you can also choose to sort by author or title.

Dibblee Collection

Dibblee Digital Geologic Map Collection  (UCSC faculty, staff & students only)

  • Purchase & download maps via the AAPG Store (non-UCSC affiliates)
  • Note: The Library also owns all Dibblee Maps in print format. All are listed in CruzCat.

Topographic Maps