"The Grand Loop" is 7 miles round trip with 1,700 foot elevation gain, but hikers can divide the walk into smaller segments. Additional trails available--the starting point for hikes is at Mitchell Canyon Staging Area.
The park may be accessed by vehicle from the Walnut Creek area (North Gate Road) as well as from the Danville area (South Gate Road).
http://www.tripleblaze.com/trail.php?c=3&i=3562