Corduroy Hills is a 6.2 mile lightly trafficked loop trail located near Danville, CA that features beautiful wild flowers and is rated as difficult. The trail offers a number of activity options and is accessible year-round. Dogs are also able to use this trail.
This rugged loop joins all or parts of the Chamise, Las Trampas Ridge, Corduroy Hills, Madrone, Virgil Williams, Del Amigo, Sulphur Springs, Trapline and Mahogany trails, leading you through an amazing variety of terrain, from sun-baked chaparral to shady forest. Some of the best views in the East Bay of Mt. Diablo are to be found on this loop, which passes through a stunted forest of scrub oak and other interesting plant communities. No bicycles or horses allowed.
This is probably the toughest hike in the Bay Area for one this short. I did it once with my wife and it was definitely the toughest trail she has ever done. A lot of variety and a little bit of negotiation of big rocks close to the top. A lot of variety in forest and views and we never saw another hiker...
I'd like to do it again tomorrow......only 400+ miles away.