Bishop Ranch Open Space features 10 miles of hiking trails near San Ramon, CA.
from 680 exit bollinger heading west. make a left on paddock dr and go to the very end and park there at the end of the court. trail entrance is right there, start heading uphill. about a 5-10 minute climb from here until you get to the water tower, then it opens up to firetrail
http://www.tripleblaze.com/trail.php?c=3&i=757