Every day, east of Highway 24’s Caldecott Tunnel, thousands of commuters hurtle–or crawl–past a fine swath of the East Bay’s glorious greenbelt, where just off the highway, the north trailhead of Sibley Volcanic Preserve invites exploration.
Skyline Trail climbs to cross over the tunnel a few yards back from its portal, hidden in dense foliage. Part of the Bay Area Ridge Trail, it’s a narrow track linking Sibley Preserve to Tilden Park two miles north, over forested and grassy watershed slopes, offering long views of Mount Diablo and Sibley’s Round Top, with a good chance of spotting a jackrabbit or a coyote.
Or go south on Skyline Trail to reach Sibley Preserve’s main entrance in less than a mile. Another trail, Quarry Road, climbs open hillsides directly to the fascinating Round Top volcanic area. (Using both routes, a three-mile loop is possible.) A map and self-guided tour brochure are at ebparks.org/parks/sibley. Take in (or walk) the human-built labyrinths in the quarries. And there’s a short side trip down to a stock pond overgrown with cattails and populated by blackbirds and (in winter and spring) frogs and newts. It’s peaceful though never silent, out of sight of, but less than one-third of a mile, from the highway.
Getting there: Exit Highway 24 at Fish Ranch Road east of the Caldecott; follow Old Tunnel Road one-third mile to parking area. Toilet provided; no bikes on trail to Tilden.