Doing the Diablo Range
Although the Diablo Range runs more than 100 miles, its heart is in Contra Costa and Alameda Counties, about 25 miles east of San Francisco. Call ahead to check trail conditions. For details and trail maps contact East Bay Regional Park District ( www.ebparks.org, 510/562-7275, or 510/635-0135) or Mt. Diablo State Park (entry $2 per vehicle; www.parks.ca.gov or 925/837-2525). Parking costs $4.
Black Diamond Mines Regional Preserve
This was the heart of the Mt. Diablo coalfields, where five coal-mining towns flourished from the 1860s to the early 1900s. To get to the black diamonds, miners dug hundreds of miles of tunnels, which still snake under these hills (though they're closed to the public). Once remote, the 5,000-acre park is now an island surrounded by suburbs.
WINTER WANDERING: Some 34 miles of trails traverse the preserve’s grassy hills; maps are available in brochure boxes in the parking lots, or at the park office headquarters on Somersville Rd. (before you get to the main parking lot). Hike up along the Nortonville Trail to the old cemetery and read the headstones’ tales of life and death in the coalfields, then head back via the Black Diamond and Manhattan Canyon Trails for a moderate 2-mile loop.
WHERE: 5175 Somersville Rd., off State 4 south of Antioch.
CONTACT: (925) 757-2620
Diablo Foothills Regional Park and Castle Rock Regional Recreation Area
On the north flanks of Mt. Diablo, this 1,024-acre park was once home to Miwok Native Americans. The park is bounded by dramatic sandstone formations―the Castle Rocks and the undulating hogback that forms Shell Ridge.
WINTER WANDERING: Begin at the Livorna staging area off Livorna Rd. in Alamo. Head up Foothills Trail to Stonegate Trail, then turn back on Hanging Valley Trail and Alamo Trail for about a 3-mile loop. It’s somewhat steep, but you’ll get a good look at the China Wall rocks.
WHERE: Main entrance is at 1700 Castle Rock Rd., Walnut Creek.
CONTACT: (925) 837-3145
Mt. Diablo State Park
The Miwok considered Mt. Diablo’s conical peak home to the eagle and coyote, and both can still be found in this roughly 20,000-acre park. On clear days, the drive to Mt. Diablo’s 3,849-foot summit is a must.
WINTER WANDERING: Just below the summit, the easy, paved, 3/4-mile Fire Interpretive Trail loop boasts one of the world’s widest vistas. Pick up a copy of the trail’s nature guide at the Summit Visitor Center (10–4 Wed–Sun). If the day is blustery, take refuge at the wind-sheltered Rock City picnic area.
WHERE: I-680 to Danville; take the Diablo Rd. exit, then drive 3 miles east to Mt. Diablo Scenic Blvd.
CONTACT: (925) 837-2525
Morgan Territory Regional Preserve
It’s a winding, lonely road into 4,100-acre Morgan Territory, just southeast of Mt. Diablo, but the scenic drive alone―through hills dotted with blue oaks―is worth the effort. Once on the trail, you feel like you’re visiting some remote, airy kingdom: most of the park sits well above 2,000 feet.
WINTER WANDERING: For a strenuous leg-stretcher, with ridgetop views of Mt. Diablo and the snowy Sierra Nevada, try the 7-mile loop on the Volvon, Blue Oak, and Valley View Trails.
WHERE: From I-580 in Livermore, take the N. Livermore Ave. exit and head north to Manning Rd. Turn left and drive about 1/2 mile to Morgan Territory Rd.; turn right and follow signs for several miles to the park.
CONTACT: (925) 757-2620
Sunol Regional Wilderness
Winter is Sunol’s prime time―gone is the heat that can ruin a hike in these steep canyons. Stop in at the old green barn visitor center (10–4 weekends) for information about the natural and ranching history. Oak groves, open meadows, and lots of steep trails mark the wildlands of Sunol Regional Wilderness.
WINTER WANDERING: Join the Sunol Wilderness Pack Station on the Valley Loop Ride ($15; reserve ahead), a half-hour guided ride into oak woodlands. 10–5 weekends; (925) 862-0175.
WHERE: From the Fremont area, head north on I-680; take the Calaveras Rd. exit; turn right on Calaveras, then left onto Geary Rd. into the park.
CONTACT: (925) 862-2601 or (925) 862-2244