Sibley's Geological Treasures: rocks telling the story of the past of the Berkeley-Oakland hills

Before you venture on a self-guided tour through the Sibley Volcanic Regional Preserve east of San Francisco Bay, get started with the history and geologic past of this unique place by browsing the interpretive panels and displays on the patio of the unstaffed visitor center at the park entrance. There, the rock display, entitled “Sibley's Geological Treasures,” shows a collection of rocks related to various events that happened during the 10-miilion-year history or volcanic eruption and mountain uplifting along earthquake faults of the Bay Area:

• Autoclastic basaltic breccia
• Basaltic breccia from top of a flow
• Basaltic breccia with limestone matrix
• Conglomerate from Orinda Formation
• Cretaceous sandstone
• Lapilli agglomerate
• Massive basalt lava
• Rhyolite tuff
• Ripple-marked pebbly sandstone
• Vesicular basalt lava

The Sibley Preserve is a great place for nature studies as well as hiking and mountain biking. It includes the  Pond Trail, Quarry Trail and Volacanic Trail. and the Bay Area Ridge Trail/Skyline Trail is going through the preserve. Along particular trail segments you may want to view and explore the many geologic features reminding you that you are on top and between ancient remains of an extinct volcano; yet an active fault system.

Pond Trail in the Sibley Volcanic Regional Preserve

The short 0.42-mile-long Pond Trail in the Sibley Volcanic Regional Preserve is a dead-end trail. The “dead-end” consists of little ponds, which are not dead at all. They are thriving with aquatic life.

The ponds are located east from where the Bay Area Ridge Trail follows Round Top Creek parallel to Old Tunnel Road. From the parking area next to Old Tunnel Road, one can ascend Quarry Road (no motorized traffic) for about half a mile and then turn left onto Pond Trail to descend to the ponds. The Pond Trail/Quarry Road junction is found near the lower end of the Quarry Road segment between Quarry Road's junction with Quarry Trail and Volcanic Trail. A hike or ride from Sibley's main entrance and visitor center via these upper ridge trails will add up to a distance of about two miles. Less, when taking Quarry Trail. More, when taking Volcanic Trail and/or the longer half-loop of Round Top Loop Trail.

Keywords: hiking, mountain biking, equestrian, network of trails,  Berkeley-Oakland hills, East Bay, California.

Trails with a view of San Francisco Bay: Sibley's Volcanic and Quarry Trail

The Volcanic Trail and the Quarry Trail in the Sibley Volcanic Regional Preserve contour the rolling ridges of the Berkeley-Oakland hills. Along these trail, hikers, mountain bikers and horseback riders enjoy the view over the lower ridge forest to the Bay with Treasure Island and the skyline of San Francisco in the background.

On a foggy day this westward view may be rather limited; but perhaps not to the east, where you can see Mount Diablo. In late summer or fall you are likely to experience the hot and dry Diablo Winds coming from there. Being located close to Oakland neighborhoods, the Sibley Preserve is a wildland urban interface (WUI), also called wooei. The preserve and neighborhoods are at a high fire risk when such winds from the east blow over the ridge.

The most spectacular features are found right next to the trails— for a geologist anyway. Fires, blasts and hot lava have ruled over the area for quiet some time, evidenced by the basalt lava blocks scattered around. You are invited to explore sites that, for example, expose Orinda Formation river gravels and mudstones, brick-red knobs, basaltic tuffs and other rocks built from lava and ash.

Sibley Volcanic Regional Preserve: volcanoes, pits, outcrops, knobs and tuffs

The Sibley Volcanic Regional Preserve in the Berkeley-Oakland hills, California, is named to honor Robert Sibley, a founder and director of the East Bay Regional Park District (EBRPD) [1,2]. The preserve includes the 1.6-miles-long Round Top Loop Trail, circling around the extinct volcano, after which this trail is named. Round Top has an elevation of 1,763 feet [3,4]. Originally the preserve was called Round Top Park and mostly limited to the area around this peak. Today, the preserve extends further northwest beyond Quarry Road to a couple of ponds and to the site of the Stephen A. Lewis bench, from where one can view Siesta Valley across Highway 24.

The most interesting features in the preserve are those left over from a 10-million-year-old volcano as well as the exposed rocks and sediments telling the geological history of the uplifting of the Berkely-Oakland hills by tectoniic forces along the Hayward and Moraga earthquake faults. The above picture shows the Round Top quarry pit, discovered by quarry operations and now exposing the interior of the Round Top volcano. At times the pit turns into a small “crater lake.” Currently, a spiral labyrinth has been crafted onto its tuff-breccia floor. Northwest of this crater pit, you'll find various numbered sites of rocks and outcrops, whose formation history is explained in the preserve flyer by referring to diverse volcanic phenomena.

Getting to the Sibley Preserve entrance, visitor center and trail junctions
The preserve entrance is located east of Skyline Boulevard, just 0.1 miles south of the Grizzly Peak Boulevard/Skyline Boulevard junction. From Tilden Park in Berkeley follow the winding Grizzly Peak Boulevard southwards, past the intersection with Fish Ranch Road until you reach Skyline Boulevard. Turn left and find the park entrance to your left. From Highway 24 take the Fish Ranch Road immediately east of the Caldecott Tunnel to get to Grizzly Peak Boulevard after driving 0.8 miles. Turn left and follow Grizzly Peak Boulevard to Skyline Boulevard as described above.
Trailheads are found on the left and the right side of the unstaffed visitor center. They are the beginning and end of a loop trail. After hiking or horse-riding either half of this loop, you get to the Round Top Loop Trail and the southward Bay Area Ridge Trail/Skyline Trail. The Round Top Loop Trail connects with further trails in the preserve, including the Volcanic Trail and Quarry Trail.

References and more to explore
[1] Sibley Volcanic Regional Preserve flyer: East Bay Regional Park District, P.P. Box 5381, 2950 Peralta Oaks Court, Oakland, CA 94605-0381.
[2] East Bay Regional Park District Map: www.ebparks.org/parks.
[3] East Bay Regional Park District > Sibley Volcanic Regional Preserve: www.ebparks.org/parks/sibley.
[4] David Weintraub: East Bay Trails. Wilderness Press, Berkeley, 1998; pp. 252-255.

From Stateline to the Tahoe Rim Trail: Van Sickle Trail

The Van Sickle Trail connects Stateline in Nevada and South Lake Tahoe in California with Heavenly and the Tahoe Rim Trail (TRT). The trail has been designed for mountain biking, hiking and equestrian sports. Although it is a connector trail between Lake Tahoe basin and the ridge and loop trails in the Carson Range around Heavenly Village and Daggett Pass, the Van Sickle Trail will delight you with a great outdoor experience even if you are only planning for a short walk: from Heavenly (Kingsbury South) to the first trail sections that offer stunning views of Lake Tahoe and surrounding Sierra peaks; or from Stateline to the waterfall (3/4 mi)—an easy to moderate climb between outcrops, boulders and through open manzanita and pine forest. Infrequently, wind from the west may carry to your ears the sound of the Heavenly Gondolas passing supporting towers.

The picture shows a westward view from an upper Van Sickle Trail spot to the Desolation Wilderness and Crystal Range, still covered with snow (June 16, 2012). The total trail length (one way) is about 3.5 miles. Until recently, the middle section of the trail was still under construction and smoothening work, yet open for “traffic.” The Van Sickle Park and Trail was opened in summer last year [1-2]. The South Tahoe Area Trail Map shows how this trail is linked with other multi-use trails, dirt roads and bike trails in South Lake Tahoe and the Heavenly Mountain Resort [3].

Getting to the lower trailheads
From Highway 50 in Stateline, Nevada, turn into Heavenly Village Way. Walk or drive through the wide-spread village and mall neighborhood to get to the intersection of Heavenly Village Way with Montreal Road (right side) and Lake Parkway (left side), where you should see a boulder with “Van Sickle Bi-State Park” written on it. Get straight into the Park, pass the interpretive area with the barn and continue until the paved road ends into a turn-around loop and parking area. The trailhead is to the right at the beginning of the one-way turning loop. Picnic tables and restrooms are available.
Van Sickle Trail may also be accessed from Saddle Road in South Lake Tahoe, California; but parking space is very limited and there are no restrooms and no trail signs (when visited on June 24, 2014).

Getting to the upper trailhead
The intersection of the Van Sickle Trail with the TRT can be accessed from the Heavenly Resort (Kingsbury South). Starting at the Stagecoach Express ski lift, as described in the East Lake Reservoir hike, take the new westward-going TRT section. There, a signpost indicates that you are half a mile away from the Van Sickle Trail Junction.

References and related pages
[1] Lake Tahoe News: Trail building day ensures July opening for Van Sickle Park [www.laketahoenews.net/2011/06/trail-building-day-ensures-july-opening-for-van-sickle-park/].
[2] California Tahoe Conservancy: Van Sickle Bi-State Park [tahoe.ca.gov/van-sickle-bi-state-park-79.aspx].
[3] South Tahoe Area Trail Map (From Kingsbury Grade to Highway 89) [mountainbiketahoe.org/wp-content/Maps/Map_SLT.pdf].

Covell Park, Northstar Park and Davis-Covell Greenbelt

The Davis Community Park at West Covell Boulevard in Davis, California, is connected with Covell Park and Northstar Park by the Davis-Covell Greenbelt. Parks and greenbelt are linked by a paved path, which is used by joggers, bicyclists, dog walkers, hikers and inline skaters. The greenbelt features playgrounds, frisbee greens, art and nature. And all is conveniently accessible from the neighborhoods through which the greenbelt circles and branches.

Dogs can be seen in most parks, but along the 2.7-mile-long loop trail of this parklike belt you'll find both realistic and amusing dogs—bronze sculptures crafted by artist Jean van Keuren. They include the shown dog at play, a dog chasing a turkey and a dog on a tricycle. While you are jogging by these dog sculptures, you may think of the sculpture that captures your activity: The Joggers in downtown Davis. 

Northstar Park, in most parts, is a wetland habitat. A short boardwalk trail leads from the loop path to a platform, from which you can overlook the wildlife habitat and the Julie Partansky Pond. Residential and migratory waterbirds inhabit the small habitat and the pond. The latter also provides flood protection as part of a storm drain system for the surrounding homes, streets and gardens.

Berkeley Rose Garden: trails in a theater of roses

The Berkeley Rose Garden is a City of Berkeley Landmark. It is surrounded by the Codornices Park, tennis courts and residential areas. The rose garden is build like an amphitheater with views of San Francisco Bay. The theater terraces correspond to planting arrangements, displaying roses organized by color, starting with red at the top and descending through bronze, pink, and yellow to white at the bottom. The many walkways and rose beds of the theater terraces are sun-exposed, while the semicircular redwood pergola provides partial shade and climbing opportunities—for roses only! One finds more shade along the small loop trail through a tiny forest (see right picture), which is located on the left side, assuming that you are overlooking the garden from the upper entrance at Euclid Avenue.

In case you are looking for other interesting plants from around the world, you'll find them in the Botanical Garden of the University of California, beautifully situated in the Berkeley Hills.

Rock Lake off Ophir Creek Trail

Rock Lake is a shallow lake southeast of Slide Mountain in Nevada. The lake can be accessed via a side trip while hiking and climbing Ophir Creek Trail, which connects Davis Creek Regional Park in Washoe County with Tahoe Meadows and the Mt. Rose Wilderness. Rock Lake is a little more than three miles away from the Ophir Creek Trailhead in Davis Creek Park. After crossing Ophir Creek, half-way from the trailhead, the trail bends back, follows the creek for a while on its south side in eastward direction and bends again, ascending westward through channels and forest. Along the rocky ledges and slopes, creeping penstemon mats—displaying their tubular purple-red flowers—can be found during late spring.  

The “lake junction” of Ophir Creek Trail is well marked: The half-mile Rock Creek Trail branches off to the north through dense forest and shrubs. The main trail continues as directed by the sign for the Price Lakes. The latter lakes are still 1.5 miles away.

Rock Lake is surrounded by forest, a few grassy patches and boulders. Rocks are also spread out over various areas of the lake. Its name is justified! Carefully hopping these rocks into central parts of the lake brings you close to the pads of yellow water lilies, which cover the open lake surface: Rock Lake becomes “Lily Pond.”