In the 1920's and 30's, Albert E. Wieslander did a natural vegetation survey in California and some adjacent areas, creating Vegetation Type Maps (VTM) and a number of other products including images. The original images are now housed in UC Berkeley's Marian Koshland Bioscience and Natural Resources Library. The library received funding in 2002 to digitize these images and associated data. See the library VTM web site and the Geospatial Innovation Facility (GIF) VTM site (beta) for additional information.

I've tracked down a few of the sites where photos were taken and took new photos. Below are links to pages with the images -- originals and the retakes.

Some of us are hoping to get more people interested in finding the original photo locations and taking new photos to see any changes in the vegetation and landscape that have happened during the intervening decades.

 

 

April 20 & 21, 2015: Photo retakes from Lake Isabella area, Kern County, CA
July 4, 2014: Photo retakes from Nevada County, CA
September 20, 2013: Photo retake from Amador County, CA
June 2 & 3, 2013: Photo retakes from Kern and Tulare counties, CA
March 29, 2013: Photo retakes from San Luis Obispo County, CA