I haven't ridden that section of trail this year yet (recovering from a fracture that's really eaten into my riding), but I do recall seeing what could best be described as a homeless stealth campsite, with a tent or two and accumulated trash back in the woods. The "R" link that Ed mentioned says that the city kicked them out of there. I've never had any trouble with the group as a whole short of having one guy walk out of the deep woods onto the trail without looking left or right. Startled me and I could have hit him if I had been going a bit faster.