Highball, did you click on the citation they give to the law ? Notice it doesn't specifically say "no metal detecting". In fact, the policy letter itself admits:
"We also don’t allow metal detecting and digging in Seattle parks.Although the Park Code doesn’t specifically cite metal detecting, SMC 18.12.070 prohibits anyone from removing (or destroying, mutilating, or defacing) lawn, sand, soil, sod, or pretty much anything found in a park."
(emphasis mine)
Ok, that relies on the "digging" and "mutilating" and "removing" verbiage to disallow md'ing. Then in that case, it's not only Seattle that can say this. EVERY CITY IN THE USA can therefore be "off-limits" . Because all cities have such boiler plate verbiage.
And I question this line:
"We know there are leave-no-trace metal detectors, but many people are not "
I wonder if they can really cite any such incident ? Of someone who left holes ? Because quite often they just say "no because of holes" ONLY because that's the knee-jerk reaction image that the average person has, when tasked with thinking about "a man with a metal detector". So for example: they pass by the park one day and see a detector (or someone comes waltzing in to ask "can I metal detect?"). And what the first thing that might come to their mind ? Holes, of course. EVEN IF THEY NEVER SAW A HOLE.
And the md'r walks away muttering under their breath: "Durned those guys that must've left holes." I'm not so sure there was necessarily cases of holes (that would've led to formalized rules anyhow).
Anyhow, this is just a policy statement (enforceable none-the-less). But so long as you left no trace (mutilate vs mutilatED), then you wouldn't *technically* be afoul of that. Yes the "remove" verbiage is harder to get around (you "remove" coins after all, eh ?). But so too is that going to be a bug at any city across the USA. Yet md'ing is common-place where such verbiage exists.
