I'm not sure where I ride. I know it's part of the Mt Diablo open space and I know that if I take the trail from the May 22 photos, mentioned above, I end up at the top of Mt Diablo, which is pictured here. It's probably 1,000 ft higher than the point I took this picture. That's the beauty of this area...from the trailhead that I start at, I can take at least four separate routes that do not end up in the same place. One of them is single track and not open to bikes (yeah), the other is the May 22 trail that takes you to the top of the mountain, another goes along that valley in the center of the picture and the fourth is the one I like, which is parallel to the highest elevation of Mount Diablo but not, technically, the top of Mount Diablo.