Get you a really long oil type drill and some tubes like those that bank drive thrus use,with a metal case.Wrap up the cash and stuff it in the tubes,drill a really deep hole.Drop the tubes down the hole,making sure they are deep enough not to be detected by common metal detectors.Measure how deep they are and cover with dirt.Now,if you ever need to dig it up ,you will know how deep to drill with out penetrating the tubes.Record the exact coordinates of the hole using some kind of code that only you understand,keep that somewhere very safe. Use a magnet at the end of an extension pole when you are ready to retrieve some of the tubes.O yea,and the Bank Of Scoops can hold some for you too so you won't have all of your eggs in one basket.Cheers
