There is signage on the ranger station at the entrance that explicitly says no metal detecting allowed anywhere in the park.
I've never seen anyone metal detecting there. I would suspect at the very least you would have to get a permit from the Ranger and probably they don't allow metal detecting. Not only is there are the occasional rattlesnake what you need to watch for there may be certain restrictions due to the amount of Indian Land that is in the area.
I would contact the park for details.
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