These images are from a recent hike at Shell Ridge Open Space in Walnut Creek. This is a well travelled location, and you'll probably see a lot of hiking clubs, trail runners, dog walkers and bikers. There is a small parking area at the end of Sutherland Drive. There were no maps at the trail head, but you can print one off here.
Trails Featured: Fossil Hill Trail, Briones Mt. Diablo Trail, and Ridge Top Trail.