I said I would never hide a magnetic key holder after all the mushy logs I have seen in them. Well, I had this one in the trunk, and found an area where it should stay dry, unless the water gets REALLY high.
Be sure to bring something with which to sign the log. Watch out for traffic, and you might want to let your GPSr settle a little bit, as my coords were all over the place. Feel free to post corrected coords if you get something different.
http://www.esu8.org/~newman/Watershed%20Project/watershed/index.htm