Don't know if they closed the range down or not.
As far as the one shot rule, last time I was at a DNR range (about 7 years ago) at Pontiac lake in Waterford. I was sighting in a scope on my AR and I had a 20 loaded up. I was taking my time as I wanted good shot placement to sight in. When this "I got me a title so I have a power trip goin' in my big head" dude came over and started yelling to me to open the action and unload. I asked him what the problem was and he started yelling about the one shot rule. At that point I told him that if I wanted to shoot one round at a time, I would have gotten a muzzle loader, but I did not like reloading that much so I got an auto loader. I guess he did not like my answer as I could tell that he wanted to throw me out. But I beat him to the punch and started packing up. Never went back to a DNR range and never will.