Sibley Volcanic Regional Preserve: 5 miles, 800 feet elevation gain

Join us for a Mothers' Day hike at Sibley Volcanic Regional Preserve, a unique gem nestled in the Oakland Hills, offering panoramic views, fascinating geological formations, and a peaceful escape from the bustle of the Bay Area. This 928-acre preserve is centered around Round Top, an extinct volcano that last erupted over 10 million years ago. Over millennia, tectonic activity and erosion have exposed the volcano's interior, creating an open-air classroom of lava flows, volcanic breccia, and ash deposits that tell the story of California’s dynamic geological history.

Our journey will take us along well-marked trails like the Round Top Loop and the Volcanic Trail, where we’ll pass through oak woodlands, grassy hillsides, and rocky outcrops. We'll make time to stop at interpretive signs, admire striking views of Mount Diablo and the San Francisco Bay, and explore features like the Mazzariello Labyrinth—a hand-built spiral path that invites quiet contemplation amid nature.

This hike is perfect for curious minds, nature lovers, and anyone looking to stretch their legs in a beautiful and educational setting. The pace will be moderate and suitable for most fitness levels, with plenty of breaks to soak in the surroundings. We're starting at the base of the park, near the Caldecott Tunnel, so it's uphill for the first half, then 'all downhill.' We'll take a short lunch break somewhere near the top.

Kids are welcome, dogs are not.

A donation of $2 is requested at the start of the hike, and I'll 'pass the hat' at the start of the hike. You are welcome to contribute any amount. This helps to cover Meetup fees and buy me a cup of coffee.

If you need a ride from Orinda BART, I can pick up people. You'll need to arrive at the BART station on the 9:44 train (if coming from the west) or the 9:52 (if coming from the east). Leave a comment if you'd like a ride.

On Saturday evening before the hike, I'll send my cell number to everyone who has RSVP'd, in case you run late and need to find us.

More details about the hike and the geology, including a map and videos, can be found at geology.trampleasure.net.