On this evening outing, we'll hike the Mary Bowerman trail to learn about the Franciscan rocks that compose Mount Diablo's lofty summit. Some of these rocks performed their first "gig" two miles deep in the ocean and are part of the Marin Headlands terrain! As we walk, we'll enjoy a 360-degree view of the Bay Area. After we circle the mountain, we'll climb the last section of the Summit trail to the museum on top.

This is an easy hike of about 1-1/2 miles round trip. The Mary Bowerman trail is narrow but fairly level. The Summit Trail is steep and rocky, but short. Bring liquids, snacks and dinner if you like. Dress in layers and wear good hiking shoes. Bring poles if you normally use them. Restrooms and water are available near the trailhead. Rain cancels.

Sponsored by California State Parks and Greenbelt Alliance

As evening falls, you'll have the opportunity to join the monthly public program of the Mount Diablo Astronomical Society and view celestial wonders through their telescopes.