Las Trampas Regional Wilderness is the tough guy of the East Bay Regional Park District. 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 and oaks. 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 Rocky Ridge, and all loop hikes make use of at least one of these trails. 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. Enter the park by the large metal gate, walk across the grass, then pass through the cattle gate onto 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 dips to cross 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 0.4 mile. Turn right to remain on Elderberry Trail.
     The trail climbs sharply uphill, first under coast live and 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, but there are several steep ups and downs on the way to the ridge. 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. 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 1.2 miles, a shortcut path (not on the map) departs uphill to the right. 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. Elderberry Trail crosses through a pretty California bay grove, then winds through the grassland and makes a final steep push to the ridge line. 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 2 miles. From the junction, savor the views east, of Mount Diablo. There's a short trail to the south that dead-ends at a belvedere (with a much-appreciated bench to catch your breath), but take Rocky Ridge View 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.
     Rocky Ridge View 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 a rocky reef jutting out of the ground on the left side of the trail. Take a close look. These rocks from the Orinda Formation hold remnants of ancient beach and shoreline. Shells are visible embedded in some of them. At 2.3 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 my old 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 Rocky Ridge View 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 2.8 miles, Cuesta Trail departs on the right side of the trail from a signed junction. Either Cuesta or Rocky Ridge View Trail is an option here. Rocky Ridge View continues along the ridgeline, while Cuesta angles along the hillside beneath the ridge (in winter spare yourself from the mud and take Rocky Ridge View). For the featured hike, turn right onto Cuesta.
    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. Ignore unofficial paths heading back down to Elderberry Trail on the right side of the trail.
     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. California bays are the dominant tree, flourishing in the damp creases of the hills. Beware a social (cow? deer?) path that heads straight where the real trail curves right and downhill, at 3.6 miles. This path starts out fine, but then deteriorates. Cuesta makes a final descent to a signed junction at 4.2 miles. Paved Rocky Ridge Road ascends from here to the ridge; according to the map a small dirt path runs along it, offering an optional route for hikers -- last time I was here I didn't see the side path at all. Turn right onto Rocky Ridge View Trail.
    Although the trail is wide and paved, it's closed to cyclists. Rocky Ridge View Trail 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: 4.7 miles
Last hiked: December 7, 2018
Previous visit: April 17, 2002 and March 15, 2000