.... is golden gate park off limits? .....
There is sometimes a confusion in the title of "Golden Gate National Recreation Area" (GGNRA) with "Golden Gate Park". Since, of course, they share the words "Golden Gate" in their title. But Golden Gate park is part of the CITY park's dept. While the GGNRA is federal (administering a few beaches in your area). Hence no, they are not the same, despite some similarity in their name's wording.
As since golden gate park is a city park, then you can refer to my prior answer: Where I let you know that SF city park's dept. has no prohibitions on md'ing (silent on the subject). It's been detected to death. Big Rec. used to be a big-producer back in the day, but got hit hard. But a lot of cherry picking for deep high conductors. Thus no one ever gets it all.
There's always going to be deeper whispers, masked targets, or persons who passed lows & mid conductors, etc.... The panhandle is especially junky, thus avoided by a lot of hunters who got sick of the clad, tabs, wino caps, etc...... If you cared to go into there and pick a 10 ft. x 10 ft. area to stripmine, I bet you'd get some old coins
And as said before: Just because no rule or prohibition exists, still does not mean you "go out and swat hornet's nests". Pick low traffic times. This is a rule of thumb for any "turf" afterall, as it could carry connotations to a busy-body.
) With some beach erosion hunting now and then (if/when we ever get any swells to rake our coast). And old-town demolition hunting can be good at times.
