San Diego hosted the Panama-California Exposition from January 1, 1915 to January 1, 1917.  The structures in the foreground are gone now, but the area where the trees are is now the San Diego Air & Space Museum.  There's a well-worn path in Cabrillo Canyon on the right, where the Cabrillo Freeway (I still call it that) is today.  I'm not sure why the top half of the image is fuzzy.  It can happen if you're making an 8 x 10 contact print if air gets under the negative.