Okie,
There is a place in eastern Oklahoma called K River Campground just north of Antlers that allows dredging, high banking, sluicing, panning, or metal detecting. It is open to anybody though I believe they charge a small fee( something like $3.00 I think). They have camp sites and a few cabins there as well. There is a club out of Greenville dredges up there a couple of times a year. I haven't been there but a good friend of mine who deals in metal detectors has been several times. He says its nice. Just thought you'd like the info.
Ty98