Its interesting that I know a guy who owns a ranch in So Cal and an F117 crashed on it. The Air Force immediately took over the area removing the debris and dug up several feet of top soil over a large area and removed that too. Last time I talked with the guy he says after many years of rain there was some visible debris in the soil and some day I would like to investigate the spot, which is only accessible by horseback or maybe motorcycle. I did some horseback riding on his property some time after the crash but didn't have enough time or info to access the crash site.
Another friend working at an aerospace company was lead on a project for some sensors and things on the 117 and the aircraft that was shot down over Yugoslavia in 1999 was his test aircraft with some of the latest one of a kind and very classified sensors aboard. Some of the remains of the aircraft made its way to the Chinese embassy in Belgrade where the warehouse was blown to bits by US bombers and blamed on wrong CIA coordinates for another area. In reality, the coordinates were spot on. The friend of mine, now passed away, had this specific aircrafts log book at his house from reviewing some of his work at home and after the crash he just kept the log book.
Oh, and to 737mech and others, thanks very much for your service!