The recently redesigned California Digital Newspaper Collection viewer offers public access to full page scans of several California newspapers for the years 1849 through 1911. One can search these newspapers by keyword or browse by date by using the calendar search option.
Currently available are the Alta California (1849-1850), Daily Alta California (1850-1876), Amador Ledger (1900-1911), Los Angeles Herald (1905-1906), San Francisco Call (1899-1910) and the Call-Chronicle-Examiner April 19, 1906 post-earthquake issue.
From the website:
"The Center for Bibliographical Studies and Research, University of California, Riverside (UCR), has received two grants from the National Endowment for the Humanities to participate in the National Digital Newspaper Program (NDNP), 2005-2009. Additional information about this program is available at the Library of Congress corollary NDNP Web site. We also received three Library Services and Technology Act grants from the California State Library to create a California Digital Newspaper Collection at UCR.
The NDNP is a joint venture of the National Endowment for the Humanities and the Library of Congress to create a national digital newspaper resource representing papers from all states published between 1836-1922. The program is projected to last twenty years. The first grant covered newspapers published between 1900-1910. The Center digitized over 100,000 pages of California newspapers for this period: the San Francisco Call, the Amador Ledger, the Imperial Valley Press, and the Los Angeles Herald. The Center will be digitizing an additional 100,000 pages for the second grant, which targets newspapers published 1880-1910.