Round Valley Regional Preserve,
East Bay Regional Park District,

Contra Costa County
In brief:
Loop through oak-dominated grassland. Good bird-watching, including golden eagle sightings.

Distance, category, and difficulty:
This 4.1 mile loop hike is moderately easy. Trailhead elevation is about 260 feet, and the park's highest (trail) elevation is about 1100 feet -- total elevation change for this hike is about 900 feet.

Some pockets of shade, but mostly full sun.

Trail traffic:

Trail surfaces:
Dirt fire roads and trails.

Hiking time:
2 hours.

Very hot in summer. Muddy in winter. Spring is nice, and autumn is good for golden eagle spotting.

Getting there:
• From eastbound CA 24 in Contra Costa County, take 680 North, and just past the 680 split, exit Ygnacio Valley Road (exit 46b). Drive east on Ygnacio Valley Road for about 7 miles, then turn right unto Clayton Road. Continue on Clayton Road (which turns into Marsh Creek Road) past Morgan Territory Road and Deer Creek Road, to the preserve entrance on the south (right) side of the road. It's about 13 miles from Clayton.
• From Interstate 580 in Alameda County, exit at Vasco Road in Livermore (exit 55) and drive north on Vasco Road about 14 miles to the junction with Camino Diablo Road. Turn left onto Camino Diablo Road, drive about 3.5 miles, then continue straight/left onto Marsh Creek Road. Drive west on Marsh Creek Road about 1.5 miles, to the preserve entrance on the south (left) side of the road.

Get driving or public transit directions from Transit and Trails:

GPS Coordinates* for Trailhead:
Latitude 3752'6.50"N
(* based on Google Earth data, shown as degrees, minutes, seconds)

Gas, food, and lodging:
Gas, pay phones, stores, and restaurants in Livermore and Clayton. No camping.

Trailhead details:
$2 parking fee. Two nice vault toilets at the edge of parking area. Lots and lots of parking, including two designated handicapped spots. Trails are not wheelchair accessible, or suitable for strollers. Maps available at the information signboard. There is no direct public transportation to the park.

The preserve's fire roads are multi-use. There is one trail closed to cyclists. No dogs are permitted. Park hours vary throughout the year: check the hours posted at the entrance. Generally Round Valley is open from dawn to dusk.

The Official Story:
EBRPD's Round Valley page.
Park office (at Black Diamond Mines) 925-757-2620

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
Afoot and Afield: San Francisco Bay Area, by David Weintraub (order this book from has a great map and descriptions of a Round Valley hike.
• David Weintraub's East Bay Trails has a good map and a featured hike (order this book from

Round Valley in a nutshell -- a printable, text-only guide to the featured hike.

View photos from this hike

Go to Bay Area Hiker Home page

Have you ever been to a ghost town? TrailheadHow about a ghost preserve? There's something about Round Valley, maybe it's the deep quiet, or the emptiness, or the abandoned farm equipment... whatever it is, this is a lonely preserve that makes for quiet contemplation, especially on weekdays. 
     Once home to California Indians, the land was farmed and ranched since the late 1800's, and a few pieces of historic farm equipment (look but don't touch) dot the landscape of this Diablo foothills preserve. Round Valley was sold to the East Bay Regional Park District in 1988.      
      It gets super hot here in the summer, so you may want to visit on a cool fall morning, when raptors are active, or in the early spring, for wildflowers in the valley (although the cows eat most of them). Miwok Trail From the first storm to the end of the rainy season,Round Valley trails are muddy.
     There is now a connector trail, crossing Round Valley Creek, that permits a second loop here.
     Many visitors are drawn to the preserve for birdwatching, and in particular, raptor observation. On my first Round Valley hike I observed a golden eagle hunting above the hillside and then sitting on top of a tree. Redtail hawks are common, and on another visit I saw a redtail flying while clutching a squirrel. If you're quiet and lucky you may see bobcats and coyotes, but you definitely will see scads of squirrels, often feasting on acorns from the preserve's many oaks.Hardy Canyon Trail These squirrels are fat and sassy, and when you disturb them they take off across the trail to their burrows as if chased by a missile. Round Valley is also protected habitat for the San Joaquin kit fox, and because these small mammals live here, no dogs are allowed in the preserve.     With the opening of the Los Vaqueros Watershed, Round Valley has become a hiker-friendly trailhead for long all day excursions to parks south and west of the preserve. Starting at Round Valley saves you the Los Vaqueros entrance fee, and there is plenty of parking. It's about 2.5 miles to the Los Vaqueros entrance, and then 1.6 more miles to Morgan Territory. You can't loop back to Round Valley, but if you hike with a friend you can create good one-way shuttle hikes by leaving a car at Morgan Territory.Hardy Canyon Trail
     Start from the trailhead at the southern end of the parking lot. A short connector path leads to a sycamore and walnut-shaded bridge. At the other end of the bridge, at 0.10 mile, signed Hardy Canyon Trail begins on the left (you can take this loop in either direction). Continue through the cattle gate and straight, on Miwok Trail.
      The broad multi-use fire road begins a climb through blue oak woodland. Much of the rock in this area is sandstone, so the trail surface is very soft in some areas, and the trail itself can be dusty or muddy -- frequent equestrian use and the preserve's range cattle contribute to bad trail conditions in wet weather. The trail crests, drops back down and then heads up again. View to Mount DiabloAt the start of the second ascent, at 0.31 mile, continue straight on a small, but established unsigned trail that runs along the fence and rejoins the main trail at the foot of the hill. The shortcut rejoins the fire road at 0.39 mile. You'll cross one of several creekbeds that crease the hillside to your left. At a signed junction at 0.49 mile an access road sets out to the right and then enters private property; stay to the left on Miwok Trail.
     Miwok climbs slightly along the creekbed, where some water remains all year long. Look for frogs, including the California red-legged frog (federally threatened), bathing in the shallow pools, and turtles sunning themselves on rocks. Buckeyes huddle in the canyons to the left; some of the deciduous trees creep out to the trail, keeping the blue oaks company. Hardy Canyon TrailA few California sagebrush shrubs grow along the creek. The hillside to the north is folded in corduroy rows, mostly bare of trees, and topped with a line of oaks. I've seen golden eagles in this part of the preserve. Take note of the interesting sandstone formations in the creekbed, and across the creek on the side of the hill: there are similar sandstone rock sculptures and corduroy hills at Las Trampas Regional Wilderness preserve, about 20 miles west of Round Valley. At 1.22 miles, the trail curls south around the base of a hill, opening up into Round Valley. Hardy Canyon Trail begins at a signed junction on the left. (If you want to explore the valley before continuing on the loop, keep going straight on Miwok Trail: the majority of the old farm equipment is strewn about the next mile of the valley, and the trail remains almost totally flat as it follows the creek. When you're ready, return to this junction.) Turn left onto Hardy Canyon Trail. Hardy Canyon Trail
     The narrow trail, open to hikers and equestrians, leaves the valley floor and begins to climb at a moderate grade. Blue oaks and grassland continue to dominate the landscape, although buckeyes are common in the hillside's creases. On the right, a sloping hillside of grass gives way to the flat valley, then oak-studded hills to the west. In autumn the grass is honey-colored, but by late winter everything is green, and some yellow California buttercups and orange fiddlenecks evade the hungry cows, blooming most abundantly near the creekbeds and draws along the trail. It's a steady ascent, not hard but with no respite either. Be sure to pause now and then for a look back to the north, as Mount Diablo's two peaks are increasingly revealed. On a November hike, prints from coyote, fox, and bobcat were clearly visible on the damp trail surface. Hardy Canyon Trail At 1.90 miles, the trail reaches a rock outcrop, then ascends via two switchbacks and passes over the top of the formation. There's a stretch of pure grassland, and the trail crests at 2.13 miles. Round Valley's highest hill sits just off to the left. A path to the right heads out of the preserve. Without much of a pause, Hardy Canyon Trail heads downhill through grassland. A path heads left toward a watering trough; stay to the right here. The descent is steady. There's a little dip near a slide area, then Hardy Canyon Trail adopts a course along a creekbed. Buckeye are common, and you might see a few toyon, California bay, and coast live oak, but this is prime blue oak territory. The trail continues a modest descent, with a very short easy uphill section. You might notice an old small earth dam, where water pools during the rainy season. At 3.29 miles,a path continues straight, while Hardy Canyon Trail veers left, Hardy Canyon Trailcrossing the creek -- you'll get your feet wet here in winter and early spring. After a brief climb, the trail levels out and angles across a hillside. Traffic noise from Marsh Creek Road is audible. You might see hawks soaring above a grassy meadow on the right. The trail curves across grassland, then reaches a cattle gate at 3.81 miles. A rough trail feeds in from the right. Now along the shore of Marsh Creek, valley oak, cottonwood, sycamore, buckeye, and willow are common. The grade is level until the last few feet, when it rises up to meet Miwok Trail and the bridge, at 4.00 miles. Turn right and retrace your steps back to the trailhead.

Total distance:  4.10 miles
Last hiked:  Wednesday, November 14, 2002