'I belileve regulations prohibit digging or using metal detectors on Park Service land'
Yeah, Park Service gets VERY testy if they see someone with a metal detector, or a shovel, or anything like that.
You can be charged not only with a crime, but you can be required to pay restoration fees to return the area you disturbed, and that can run into a LOT of money.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.