Las Trampas Regional Wilderness,
East Bay Regional Park District,
Contra Costa County
In brief:
4.6 mile loop over sharply rolling, rocky hills. Great views and wildflowers in spring.

Distance, category, and difficulty:
This 4.6 mile loop hike is moderate. Trailhead elevation is about 1040 feet. The featured hike climbs to about 1880 feet and then descends back to the trailhead. There are numerous short, somewhat steep ascents and descents, and the total elevation change is about 900 feet.

Some shade, but mostly exposed.

Trail traffic:

Trail surfaces:
Dirt trails and one paved fire road.

Hiking time:
3 hours.

Late winter through spring. Trails are very muddy after heavy rains.

Getting there:
From eastbound CA 24 in Contra Costa County, exit south Interstate 680 (exit 15a). Drive about 10 miles and exit Crow Canyon Road (exit 36). Drive west (right) for about 1 mile, then turn right (north) onto Bollinger Canyon Road. Continue about 4.5 miles to the trailhead at the end of the road.

Get driving or public transit directions from Transit and Trails:

GPS Coordinates* for Trailhead:
Latitude 3748'57.14"N
122 3'0.27"W
(* based on Google Earth data, shown as degrees, minutes, seconds)

Gas, food, and lodging:
Gas, stores, restaurants, and pay phones back on Crow Canyon Road. No camping.

Trailhead details:
Large parking lot. No entrance or parking fees. Portable toilets, maps, and drinking water at the edges of the parking lot. There are two designated handicapped parking spots, but the trails are not well-suited to wheelchairs. There is no direct public transportation to this trailhead.

Bicyclists are allowed on about half the trails, but some trails are designated for equestrians and hikers only. A few are hiking-only. Dogs are permitted. Las Trampas is open from 5 a.m. to 10 p.m.

The Official Story:
EBRPD's Las Trampas page.
Park headquarters 925-837-3145

Map/Book Choices:
This hike is described and mapped in 60 Hikes within 60 Miles: San Francisco, by Jane Huber (yup, that's me, the creator of this website). Order this book from
Map from EBRPD (download the pdf).
A Rambler's Guide to the Trails of the East Bay Hills, Central Section, published by The Olmsted & Bros. Map Co.
Afoot and Afield: San Francisco Bay Area, by David Weintraub (order this book from has a great map and descriptions of a Las Trampas hike.
East Bay Trails, by David Weintraub, has some good maps and trail descriptions (order this book from
East Bay Out, by Malcolm Margolin, has a slightly outdated map and good descriptions of trails (order this book from

View 58 photos from the featured hike.

Go to Bay Area Hiker Home page

Las Trampas Regional Wilderness is the tough guy of the East Bay Regional Park District.A view of the trailhead from Rocky Ridge Trail  There are no steam trains or petting zoos. Just steep, rugged trails, interesting geology, and fantastic views. Las Trampas (Spanish for the traps) has two distinct areas, each with its own personality. Rocky Ridge, on the west side of the valley, is known for views in all directions, unusual rocks, and green rolling hills lightly forested with California bays, oaks, and maples. The wildflower display on the hills just off the ridgeline is an east bay favorite. The Las Trampas Ridge, to the east, is quite different, featuring a plant community dominated by chamise, with other chaparral plants such as manzanitas and coyote brush. On the Rocky Ridge side, there are two trails that climb to the ridgeline, Elderberry and Rock Ridge, and all loop hikes make use of at least one of these trails. A rare flat stretch on Elderberry Trail On the Las Trampas Ridge side, there are many loop possibilities, most of them long, tough hauls. A 7-mile loop that covers both sides of the ridge combines Chamise, Mahogany, Trapline, Sulfur Springs, Amigo, Virgil Williams, Madrone, Corduroy Hills, Las Trampas Ridge, and the Bollinger Canyon Trails. The shortest loop strings together Chamise and Mahogany Trails, a 1 mile hike. The easiest loop of all at Las Trampas combines the Bollinger Canyon and Creek Trails, a nearly flat 1.2 mile hike. Las Trampas is sun-baked in the summer, and the trails are annoyingly muddy in the winter and early spring (especially in areas where the cattle graze). The best season is spring, after the trails have dried out a bit, but before it becomes hot.
     For the featured hike, start at the western edge of the parking lot, near the shady picnic area. California bays on Elderberry TrailEnter the park by the large metal gate, walk across the grass, then pass through the cattle gate on unsigned Elderberry Trail. Right away you'll get a sense of the trail quality. If the surface is squishy, muddy, and/or rutted, expect the same from the rest of the trail. To the east Chamise Trail is visible as it switchbacks uphill. Elderberry Trail crosses over (through may be a better word) the first of many seasonal creeks near a buckeye tree. After leveling out across a meadow, the trail passes a corral and reaches a signed junction, at 0.42 mile. Turn right to remain on Elderberry Trail.
     The trail climbs sharply uphill, first under coast live and black oak as well as California bays near a creek, then emerging into grassland with views up to the ridge. After the initial climb, the trail curves slightly south and tapers out a bit. The worst muddy sections occur where the trail dips down to shaded creek crossings, and then climbs back up. I've hiked through here when the mud has been that industrial strength shoes-sucked-off-your feet quality. View south along Upper Trail It's not too much fun, but those stretches are brief, and the trail returns to the grassland and all is forgiven, for now. Along the trail in spring you may see paintbrush, purple bush lupine, and California poppy. Sunny stretches harbor sagebrush, coffeeberry, and poison oak. Where the trail is deeply shaded, gooseberry bushes flourish along with nettles, beneath California bays and a few maples. At 1.19 miles, a shortcut path (not on the map) departs uphill to the right, leading to Cuesta Trail. Continue straight on Elderberry Trail, which continues to rise and fall through trees and grassland. Look for deer, coyote, and bobcat tracks at the muddy spots. Poor draining soil has resulted in a few landslides on both side of the trail in one or two places. Elderberry Trail crosses through a pretty California bay grove, then winds through the grassland and makes a final steep push to the ridge line. A few old big-leaf maples, somewhat out of place on the exposed hillside, stand downslope on the left. On a mid-April hike, I saw filaree, fiddleneck, California poppy, and creamcups on the hill to the right. Elderberry Trail ends at a signed junction at 1.85 miles. Cows on Upper TrailFrom the junction, savor the views east, of Mount Diablo. There's a short trail to the south that dead-ends at a belvedere, but take Upper Trail uphill to the right.
     With unobstructed views to the southwest, Rocky Ridge is the best site for a glimpse of the East Bay M.U.D. property that is largely closed to the public. From this ridge soft-looking hills roll downhill to Upper San Leandro Reservoir, and end at Anthony Chabot Regional Park. A few trails are open to the public, but you must obtain a trail use permit from East Bay M.U.D. before heading out on any trails. I've been pinning to hike from Las Trampas to the Chabot Staging Area for a few years, but it's a long trek; about 9 miles one way.
      Upper Trail climbs steeply through the grassland, to a series of crests. It may be windy along the ridge. Once on a March hike, I watched a UFA (unidentified frolicking animal) across the canyon to the west. I had forgotten my binoculars, but could see the large dark creature was unaccompanied by a human. Bigger than a coyote or a bobcat, could this be the mythical black panther? You might notice some rocks jutting out of the ground on the left side of the trail. Upper Trail Take a close look at them. These rocks from the Orinda Formation hold remnants of ancient beach and shoreline. Shells are visible embedded in some of them. At 2.23 miles, Devil's Hole Trail departs to the left at a signed junction. If you want to extend your hike, Devil's Hole Trail drops down the west side of Rocky Ridge and passes the wind caves, an ominous-looking cluster of rocks (it's shown on the Olmsted map, but not on the EBRPD map). Then Sycamore Trail climbs back to the ridgeline and adds about 2.5 miles to the featured hike. Today, continue straight on Upper Trail.
     After a steady climb along the ridge, Upper Trail descends along the east side of the hill. On a breezy day, you'll be glad for a respite from the wind. The grade levels out, and at 2.62 miles, Cuesta Trail departs on the right side of the trail from a signed junction. Either Cuesta or Upper Trail is an option here. Upper continues along the ridgeline, while Cuesta angles along the hillside beneath the ridge. For the featured hike, turn right onto Cuesta.Cuesta Trail
Cuesta is open to hikers and equestrians only. The narrow path initially doubles back to the south, descending steeply through coyote brush, then turns and heads north. The trail has some dips up and down along the way, but mostly follows a downhill course. Cows use the path frequently, so even though it traverses an exposed slope, sections of Cuesta are soggy and rutted in winter and early spring. Views of Mount Diablo and Las Trampas Ridge accompany your descent. A spur back down to Elderberry Trail is visible on the right side of the trail at 2.81 miles. Continue straight on Cuesta.
     In late winter, milkmaids, California poppies, California buttercups, and shooting stars enliven the green grass. Later, in spring, you might see woodland star, purple bush lupine, mule-ear sunflowers, fiddlenecks, and creamcups. Rocky Ridge RoadCalifornia bays are the dominant tree, flourishing in the damp creases of the hills, but look for a magnificent, sprawling big-leaf maple on the right side of the trail. Cuesta makes a final descent to a signed junction at 4.04 miles. Paved Rocky Ridge Road ascends from here to Upper Trail; a small dirt path runs along it, offering an optional route for hikers. Turn right onto Rocky Ridge Road.
Although the trail is wide and paved, it's closed to cyclists. Rocky Ridge Road is popular with folks exercising and walking dogs; the moderately steep grade ensures a good workout. As you descend through the grassland bordered by coast live oaks, there are nice views right, uphill to Rocky Ridge, and left, to Las Trampas Ridge. Rocky Ridge Road ends at a cattle gate, back at the trailhead.

Total distance: 4.56 miles
Last hiked: Wednesday, April 17, 2002