ok, that makes sense (I posted my last message before I saw the one with the map). I saw the cement foundation at the top. There was a wooden overlook too (I looked back at it thinking it was a trail and lost my momentum and had to walk yet again). several rock outcroppings with little trails to them, overlooking the river far below.
Along the river, in the flat sandy part on the left hand side of the road, there were also some singletrack trails by another large cement thing or foundation. There was a network of trails in there and I didn't have time to ride on all of them, but the little dips and small rooty parts was fun.
vickie