"For sure if you can go to a mine and sift through it or a park site (Arkansas is famous) then do it."
Make damn sure it's legal. just because a mine looks abandoned doesn't mean you can pick up rocks, stones, gems, ore, etc.
if a mine is private property you need permission.
if a claim active you need permission
you must do your research to find out land use and ownership. DON'T ASSUME, the burden to figure it out lies on the prospector.
if you are on a claim you can camp, hike, hunt, fish, or do anything that you could legally do on the surrounding land that is not claimed. However you CANNOT even pick up a rock.
highdesertranger