http://www.lib.utexas.edu/maps/california.html
http://aqicn.org/map/usa/Airnow.gov
https://www.airnow.gov/
American Memory
Online Archive of California
http://oac.cdlib.org/search.findingaid.html
http://maps.conservation.ca.gov/cgs/gmc/
David Rumsey Map Collection
http://www.davidrumsey.com
https://www.usgs.gov/products/maps/geologic-maps
Map Collections from United States Library of Congress
http://memory.loc.gov/ammem/gmdhtml/gmdhome.html
Historical Maps ( UC Berkeley)
Maps, Atlases, Aerial Images, and Cartographic Resources ( UCLA Library)
https://calisphere.org/ - Your gateway to California’s remarkable digital collections. Calisphere provides free access to unique and historically important artifacts for research, teaching, and curious exploration. Discover over two million photographs, documents, letters, artwork, diaries, oral histories, films, advertisements, musical recordings, and more.
The collections in Calisphere have been digitized and contributed by all ten campuses of the University of California and other important libraries, archives, and museums throughout the state.
Cal State LA Library