According to the "X-Hunters" Aviation Archaeology Team, the Richard Bong P-80 wreck site is actually on the property of the Los Angeles Department of Water and Power. The X-Hunters have recently received permission to access the property where the P-80 crashed in an effort to pinpoint the actual site.
See this link:
http://pacaeropress.websitetoolbox.com/post?id=3576253
The X-Hunters, Tony Moore and Peter Merlin, are two very experienced California wreckfinders and are well respected in the wreckchasing community. Their specialty is finding and documenting the wreck sites of the X-planes (X-1, X-15, etc) near Edwards AFB. If anybody can find the spot where the Bong P-80 crashed, it is these two guys.
I just finished reading their excellent volume:
"
X-Plane Crashes."
TonyM.