I ran across this article today, its pretty interesting. Its definitely worth more than anything we would find in our backyard! Do they make wood detectors?!?!
http://seattletimes.nwsource.com/html/localnews/2003693024_stoneforest04m.html
http://seattletimes.nwsource.com/html/localnews/2003693024_stoneforest04m.html