Interesting page with photos of abandoned air crash sites. Most of the crash sites depicted on this site occurred in the high deserts of California. Many of them have been there since the early 1940's. Those who explore these sites encourage visitors to not take "souveniers" from the sites. Many of these sites are sovereign ground where men who served their country have died. Explorers are encouraged to leave the sites undisturbed out of respect for the men who served.
In any even it is quite interesting...
http://www.ghosttownexplorers.org/ai...ft.htm#harvard