Birm trail features 2 miles of hiking trails near Concord, CA.
Go up yagnacio vally road to the set of lights at the top. Go on to the land to yor right. There will bee a very large damn/retainer wall at the very back. To to it, hike up to the top, their will be a trail that gos relativly straight go up that it will take you up to the top, their will be a trail to your right and that is it!
http://www.tripleblaze.com/trail.php?c=3&i=710