I recently went to a local park. I had checked the city website and saw absolutely no regulations regarding detecting or removal of items. While I was gearing up, a ranger rode by on horseback and, feeling responsible, I walked up and asked if it would be ok (the whole time knowing the answer should be yes).
"Well, they really don't like you doing it. They caught a guy a while back digging a big hole...(he went on about some other infractions)"
"What about (the name of another area of the park)?", I asked.
"I would guess the whole area", was his response, "but you can hunt in the areas that are less frequented."
He did give me some suggestions of some other properties that he knew would be ok.
I packed up and left. A few days later I was back and was hunting the same area. The same ranger rode by and waved. Didn't even stop.
My point is, I did my research and knew I was in the right. Several park employees have been in the same area and not even glimmer of discontent. Until I am told flat out to leave, I will continue to hunt the park.