Long, strenuous hike in Mt Diablo area. Goes though green rolling hills in spring.

Location: Mount Diablo State Park — Shell Ridge Open Space Preserve — Diablo Foothills Regional Park — Morgan Territory Regional Preserve — Round Valley Regional Preserve

» REI Map for Mount Diablo and Los Vaqueros: Sold for $7.00 in April 2011. The map is very detailed, water-proof and tear-proof. Must have for avid hikers.

» Official Park Brochure: Decent map but missing myriad other trails that are shown on the REI map.

Route in brief: Follow Briones Diablo Trail all the way from Shell Ridge Open Space Preserve to Round Valley Open Space Preserve.

Notes: Water is available at only one point along the trail. At about the eight mile mark, before reaching Curry Point, a small detour in 'Rock City' is necessary to get water.

Location: Outside Indian Valley Elementary School, 551 Marshall Drive Walnut Creek , CA 94598 . Parking area is visible in Google Maps if you zoom in sufficiently.

Directions: See Google Maps. Park along Marshall Road for access to Shell Ridge Open Space Preserve.

Google Maps:

Parking Fees: None (last visited: October 2010)

Capacity: Over ten cars may be parked along Marshall Road.

Latitude: 37.901530     Longitude: -122.032042

Location: 19450 Marsh Creek Road, Brentwood, CA 94513 . Parking area is visible in Google Maps if you zoom in sufficiently.

Directions: From I-580 East, take exit 55 for Vasco Road towards Brentwood and follow signs for N Vasco Road. After 14.6 miles, turn left on Camino Diablo Road and drive 3.6 miles. Continue along Marsh Creek Road for 1.5 miles to reach Round Valley Regional Park entrance on left.

Google Maps:

Parking Fees: None (last visited: April 2011)

Capacity: More than 20 cars.

Latitude: 37.870034     Longitude: -121.750145