Images: front and detail of 1939 postmark on postcard.
Learn about the Mt. Wilson Observatory at https://www.mtwilson.edu/about-mwo/ .
See some “found film” photos taken on Mt. Wilson in 1939: http://www.foundfilmsociety.com/dt_gallery/mt-wilson-1939/ .
Image: 1939 Cedar Lake postcard.
Cedar Lake is in the San Bernardino mountains in the vicinity of Big Bear Lake. Learn more at http://www.campcedarlake.com/about-us.html . It was the location site of many movies, including several shot in 1938 and 1940 but apparently none in 1939 — see the link for details.
Image: Art by Roy Lawhorne. Published/sponsored by local Seaside Oil Company (aka Seaside Gasoline), later acquired and then dissolved by Phillips Petroleum.
Old Spanish Days was a celebration of the early history of Santa Barbara.
Image: 1939 photo from unknown source and location.
See a color photo of a 1939 Sunbrite Cleanser wagon in a museum at https://www.flickr.com/photos/mr38/4877978335/ .
Venice Beach south of Ocean Park pier.
“Dick” Whittington photo from USC Digital Archives.
Read about being a lifeguard in 1939 at Venice Beach here: http://countyrecurrent.blogspot.com/2010/06/lifeguarding-and-way-it-was-by-cal.html .