Metal detecting is prohibited as posted. Metal detecting has been allowed at Fort Mason though. You might want to contact the people in charge of that historic site to see if it is possible.
I recall there's a sign explicitly stating it's prohibited.
No, metal detecting is not allowed...Your not allowed to remove or disturb anything at the site
Not that i am aware of seeing that it a state historical site. But you can always contact the historic society to find out for sure.
Thanks! Your answer is awaiting moderation.