Mostly all two-tracks. Some single tracks. Not a lot of elevation change. Some of it is pretty sandy. Nice views as it winds around the river and there is a suspension bridge and a covered bridge. There is camping there (brought back memories from when I was a boy scout a long time ago). Probably good exercise if you live close, but not very challenging.
M-20 West of Mt Pleasant a couple miles. It covers between Winn Rd and Vandecar Rd. and the entrence is halfway between those roads on the south side of M-20. There is a sign right on M20, and a gatehouse. I think it costs a few bucks during the day if the gatehouse is manned.
http://www.singletracks.com/item.php?c=1&i=3961