Jerry L. Schneider's great website Movie Making Locations Plus has posted the story (with photos) of Lasky Mesa. It was a historic movie location ranch apparently established by the Jesse Lasky-Famous Players Co. in 1914. Gone with the Wind and other classic films had scenes shot there. We know the locale now as Ahmanson Ranch, the new public park adjacent to Woodland Hills at the west end of Victory Boulevard. Here's another link and a site with current photos. Thanks to Lou Marino for the pointers.