You do realize how lists like this came into being, don't you ? The first attempt at such an undertaking was back in the mid 1980s. When an author named Doc R. Grimm made the book: "Treasure Laws of the United States". This was in an era before internet, so the way he compiled his state by state listing, was simple:
He xeroxed off 50 copies of a letter, that was sent to the each state park's headquarters. It asked "What are the laws regarding the use of metal detectors in your state's parks?". And once he received 50 replies, he merely put them in his book, in alphabetic order. In the exact letter-head format that the state's replied with. So that you could show any busy-body who hassled you.
Genius idea, right ? And now travelers could roam state to state, and never have to wonder, right ? And who better to ask, than the states themselves , right ? And subsequent lists ever since them (like this FMDAC one) either drew from such already-existing lists, or sought added info. from the powers-that-be, in the same fashion/method that Grimm did.
Admittedly, some of the states that had a "no" in their column, did, in fact, have specific verbiage in their codes to that effect. But oddly, some of the states that had dire sounding verbiage (or out-right no's), had never been a problem before. Nor did they have any *specific* language that prohibited md'ing. Thus if you click through the list on the "no's" (or "ask at each kiosk", or "with permission only" or any other such dire restrictions), you will often see nothing that actually says those things. Instead, whoever answers the "pressing question" draws on ancillary verbiage they think applies. Eg.: "alter and deface" or "harvest and remove", or "cultural heritage", et... Yet nowhere was it written that permission was needed from each kiosk. And nowhere written "with permission", and so forth. Thus obviously a lot of those answers were just "safe" answers, from some pencil-pusher who probably passed this question in front of a bored purist archie, or someone who envisions geeks with shovels, etc... Hence the "safe" answer type of psychology.
So when that book came out, old-timers were left scratching their heads thinking "since when?". And to this day, there are several of the states with dire wording where, it's not an issue. Hence I put very little stock in those lists, unless there is actual specific wording they can cite that truly says whatever the single-words answer was.