I have been in contact with the local city parks and recreation director regarding MD'ing in parks in the city I live. Her response was "metal detecting in this city is officially illegal". When I asked her what law states that, she pointed me in the direction of the local municipal code. Within that code, there is NOTHING that says using a metal detector is illegal, but what she added was that "damaging the grass" was a municipal code violation. I guess digging is illegal ....
Well here we have it folks. Another "case example" of the phenomenon of : "No one cared till you asked".
Cal-Reg : I got news for you : If those "deface" and "alter" type boiler plate minutia means "No md'ing", then there's not a single park in the entire USA that doesn't have the same wording (in some form or fashion). And it might even use the evil word "dig". But seriously : If you leave no trace, then presto, you haven't alter
ED or defac
ED or d
Ug anything, right ?
I'll bet that the gal you talked to probably never gave the matter a moment's thought before you came in with the "pressing question". So the images of "holes" come to her mind, so she reaches for the "safe answer". I've seen this happen over and over in my 45-ish yrs. of md'ing.
And I notice that you're from San Jose, right ? Was it the city of San Jose that you were inquiring about (or one of the other cities in the south bay area ?). If it was San Jose proper, are you aware that there is actually a permit issued for San Jose city parks ? It used to be passed out via the san Jose club. But that club went defunct about a year ago, I think. Yet you can get the straight from city hall somehow still, I think.
But the dirty little secret is : No one there can EVER remember ever getting "carded " to show it. And you'll be hardpressed to find someone in city hall to even know what you're talking about (since the club used to administer them, and give the city a single check, 1x per year. But since there's no club anymore, I'm not sure how it's done now)
Trust me: You can detect San Jose area parks till you're blue in the face. I'm an hour south of you and have hunted parks there all the time (although there's no longer any good ones IMHO). Just don't stick out like a sore thumb. Pick low traffic hours. Don't be in the middle of deep holes if busy-bodies are watching.
And in the future, just look up laws/rules for yourself. If you don't see anything that says "No md'ing", then presto: Not disallowed.