Online Archive of California

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About Online Archive of California

The Online Archive of California (OAC) provides free public access to detailed descriptions of primary resource collections maintained by the Sonoma County Library, plus more than 200 other contributing institutions including libraries, special collections, archives, historical societies, and museums throughout California and the University of California.

Getting Started

  • Click on the GO button above


  • All resources are freely accessible, no registration required.
  • Guides (finding aids) to more than 140 of the library's archival collections.
  • Access to hundreds of collections owned by archives, libraries, and museums from across California.
  • Browse, locate resources, view selected items digitally (the OAC contains more than 250,000 digital images and documents), and learn how you can gain access to the physical objects.

Available for Use On

  • Desktop computers
  • Mobile devices
  • There is no app for this resource

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