ONETON: It's not gold, but Desoto Caverns State Park near Childersburg,Al. has quite a history. I don't know whether you can MD there but you can pan for gems & fossils.
History: Indian Burial Grounds
1723 Graffiti in Cave
Confederate Gunpowder Mine
Onyx Mine
Speakeasy during 20's w/ Moonshine, Square Dancing, & Gambling
I don't know how big the park is, but w/ that history it may pay off.