Hey Pirate, they will do worse than make you walk the plank for sure. Prairie Creek and Fern Canyon are truly beautiful place here on the north coast of California. If you want to see some of the biggest trees in the world and trophy Roosevelt Elk come visit these places, but don't pan for gold in Prairie Creek.
If you would like to do some panning for gold in redwood country come a little further north and try the Smith River. Here too we have great trees, huge elk and fantastic salmon and steelhead. It's pans and hand tools only (Six Rivers National Forest) in one of the most beautiful rivers in the country.
I was working beside the Smith River the other day and along a riffle of about 300 yards in length, there was a bald eagle, a golden eagle, a red tailed hawk and a couple crows. The eagles and the hawk were all perched in trees pretty much evenly spaced along this run and the 2 crows were pestering the hell out of the red tail. The eagles were hoping for an unaware steelhead. Quite a sight, I'll remember it always.
Mike