Well I am not going to bother to register but the pic you've attached looks pretty tasty!
I went to the Bloomers trail in Rochester Hills, MI and it was not nearly as interesting as those I have ridden at Loch Raven Reservoir near Towson, MD. It was short too... or maybe I just did not find the right one?
2004 Trek 4600, 1980's Univega Supra Sport, 2006 Lemond Reno
That is the expert only rock section. It is basicly singletrack that goes over boulders and rocks of all sizes. I tried to upload more pics but they were too big. I'll see what I can do later on today.