Guides to over 20,000 collections housed in 200 libraries, archives, historical societies, special collections and museums across California are searchable at the Online Archive of California (OAC). Collection guides, also known as finding aids, are descriptive guides to archival (primary source) collections. These collections may be physically located in archives or digitized on the web. The guides help users learn more about the scope of a collection so they know if it is likely to meet their research needs.
Digitized versions of photographs, documents, newspapers, political cartoons, works of art, diaries, transcribed oral histories, and other cultural artifacts that are contributed by these California institutions to the OAC make up the content included in Calisphere.