Tuesday, October 13, 2015
*East Bay residents have a volcano in their backyard at Sibley Volcanic Regional Preserve. Originally called Round Top Park, Sibley shares with Temescal and Tilden the distinction of being one of the East Bay Regional Park District’s original parks. The preserve was later named in honor of Robert Sibley, who helped found the District and served for 10 years on its board of directors.
*Softer sedimentary rock from the Orinda Formation eroded away, exposing the Round Top volcano. In addition, quarrying in the north half of the preserve has revealed cross sections of the bedrock geology, providing an unsurpassed outdoor laboratory for studying volcanism in the Central Coast Ranges.
This trail hike goes up to Round Top Peak on the Round Top Loop Trail before traveling on the ridge along the Volcanic Trail to Quarry Rd. It drops down from the ridge for a scenic hike through the woodland along Round Top Creek on the Skyline Trail. The 1763 foot Round Top peak is the remains of an ancient volcano.
Start this hike from Sibley Staging Area at Robert Sibley Volcanic Regional Preserve.
Begin on the Overlook Trail; the paved 600′ ADA path leads to a viewing platform north of the Visitor Center.
At the Backpack Camp junction-go straight to stay on Overlook Trail; the trail leads out onto the paved Water Tank Rd.
Cross the paved road-at the Round Top/Volcanic Trail junction, go straight towards Round Top Loop Trail followed by an immediate right at the next trail marker. The narrow trail cuts through the exposed tree roots of the pine and oak/bay woodland before emerging out towards the eucalyptus stands-watch your footing!
*Round Top, one of the area’s highest peaks, is made up of lava and volcanic debris left over from a 10-million-year-old volcano. During the past 10 million years, massive tectonic forces on the Hayward and Moraga earthquake faults uplifted the Berkeley hills, folding bedrock formations and tilting the Round Top volcano complex on its side.
The trail continues on somewhat rocky terrain as it winds around the eucalyptus trees.
Round Top Loop Trail leaves the woodlands behind with a steep climb up to the cattle gate and on-wards to the open summit grasslands at Gudde Ridge.
Turn left at the top of the ridge and enjoy the fantastic views before dropping down to a T junction.
At the junction-turn right onto Quarry Pit Trail for an out & back trek to the quarry pit & labyrinth.
Quarry Pit and Labyrinth:
Return to the T junction and make your way to the fenced overlook area: from this vantage point you can view the entire labyrinth from below and Mt Diablo from the southeast.
Stay on Round Top Trail Loop-it takes you along the top of Round Top to the next trail junction. *Round Top Loop Trail circles Round Top peak.
At the Quarry/Volcanic Trail junction-turn right onto Volcanic Trail. If you’re doing the self-guided geological tour, look for the numbered posts that correspond to the park’s trail map descriptions. There are many unmarked paths around the volcanic craters, use caution and watch out for the steep drop-offs into the pits! *Volcanic Trail, once a quarry haul road, contains most of the stops on the self-guided volcanic tour.
This broad trail opens up with gorgeous panoramic views of the surrounding hillsides and dense forest to the northwest. You’ll see Volmer Peak at Tilden Park, Siesta Valley and Mt Tamalpais in Marin County!
Volcanic Trail leads you around the stark volcanic landscape pass a couple of vista point benches to a cattle gate.
Cross the gate and stay on Volcanic Trail, it continues around the volcanic center to a wide open flat gravel area. The trail merges onto the paved Quarry Rd.
Quarry Trail wiggles down into the valley to Old Tunnel Rd Staging Area with views of Hwy 24 and Fish Ranch Rd.
At Old Tunnel Staging Area-turn left and enter through the trail gate onto Skyline Trail. The trail goes underneath the beautiful shaded canopy of oak/bay trees to the dry Round Top Creek crossing.
The trails continues to gently wind along the lush riparian landscape and dense woodland around Round Top Creek.
At the tiny bridge crossing, the trail tilts up for a gentle climb up towards the eucalyptus grove.
Skyline Trail emerges out of the woodlands back to the trailhead at Sibley Staging Area parking lot.
This is a wonderful easy hike around one of the three original Regional Parks. Take a park pamphlet from the unstaffed visitor center and enjoy the preserve’s geological features! Don’t forget to check out the 2 labyrinths on this self-guided volcanic hiking tour-it’s there to amaze you!
3.8 Miles with 627′ of elevation gain
Time: 2 hours
Parking: No fee at Sibley Volcanic Regional Preserve-Sibley Staging Area off Skyline Blvd in Oakland.
Water & restrooms available
Dog Friendly-On & Off-Leash trails
Bring plenty of water & food/snacks
Weather: Sunny and warm with temps ranging from the low 70’s to the mid 80’s with SW winds.