From the MM homepage: "McCaslin Mountain Campground offers direct access to local ATV trails in Oconto County, however, the ATV and 4-Wheel Drive Trails on the mountain behind the campground have been closed permanently of May 1st, 2010."
I didn't know it was closed and there isn't an explanation on the website. It was always a fun, low-key, uncrowded place to camp and wheel for a weekend.
McCaslin was always sketchy. Never really knew exactly who's land I was on or if the camp ground had any right to charge for access. It is pretty technical terrain, but the constant basketball sized boulders are annoying for leaf sprung YJs.
That said, I much prefer the pipeline outside of Crivitz. The variety of terrain offers a multitude of challenges and fun, and more importantly, the trails run North-South, so there is no confusion as to where you are!
Anywho, those are the two areas I am most familiar with up here in NE Wisconsin.