Are you planning on going to the GPAA Silverton Claim or BLM land? The GPAA Claim in Silverton is open to metal detecting, as is BLM lands, but the BLM has specifications on how much material you can remove. They allow for fossil, rocks, mineral, and treasure hunting but have restrictions on the amount. I would give the Colorado BLM office a call at 303-239-3600

I should not have to tell you to be careful not to dig on somebody else's claim or National Park property without written consent, they tend to get a bit excited. I have seen a lot of very well marked claim markers and other times I know I am on a claim but it is not marked at all.

You probably will have a better chance at finds down towards Silverton because of all the old Mining Activity, just my opinion, but have fun and watch out for snakes, they are out and about and like to lay under the rocks we tend to look for gold in.