6.2 miles: Waterfalls on east side of Mt. Daiblo

The rain has fallen, and the waterfalls on the east side of Mt. Diablo should be flowing!
***** Route change ******
I created a new route on AllTrails that takes us up a ridge trail to get to the waterfalls 'faster.' I haven't hiked the ridge portion before, but it looks very doable. This cuts the route back to 6.2 miles, closer to our original 5.5.
***** Route change ******

This 6.2-mile trek offers a world-class look at the Mount Diablo Ophiolite, a rare fragment of ancient Jurassic oceanic crust that has been thrust upward to the mountain’s summit. As we tackle the 1,161-foot elevation gain, we will transition from the relatively young, crumbly mudstones of the Knoxville Formation into the rugged "hard points" of the mountain's core. The trail serves as a vertical timeline, revealing how the collision of tectonic plates roughly 165 million years ago scraped deep-sea floor materials onto the edge of the North American continent, creating the dramatic topographical relief we see today.
The highlight of the hike is the Falls Trail, where the geology directly dictates the hydrology. Here, the seasonal streams flow over incredibly resilient Pillow Basalt and Radiolarian Chert. The basalt, formed from underwater volcanic eruptions, provides the dense, dark green "steps" for the waterfalls, while the ribbon chert—composed of the silica skeletons of microscopic marine organisms—creates the jagged, folded cliffs. These rocks are far more resistant to erosion than the surrounding shale, forcing the water to leap over these structural "islands" in a series of picturesque cascades that are only active after significant winter rains.
Beyond the waterfalls, the trail offers a botanical masterclass in Serpentinite geology. As we traverse sections of California’s state rock, notice the change in vegetation; the magnesium-rich, calcium-poor soil derived from serpentinite creates a "serpentine barrens" effect that supports rare, endemic wildflowers found nowhere else on earth. This hike isn't just a physical challenge; it is an immersive journey through an inverted geological sequence, where the oldest rocks sit atop the youngest, providing a rare window into the violent tectonic forces that shaped the Diablo Range.
More details:

• I've set a limit of 30 people; with the usual no-show rate this should keep the group to around 15-20. If you RSVP Yes and your plans change, please change your RSVP to no.
• Ending time is approximate; each trip depends on the speed of that group.
• Generally there is plenty of parking, but it may be limited if there are lots of people heading to the waterfalls: Make sure you don't block people's driveways.
• Be ready for muddy, narrow trails.
• Link to trail description on AllTrails.
• The route is a 'lollypop' route: We start up one trail for about 1.5 miles, then a 2.5 mile loop that contains several waterfalls, then back down the original trail.
• $2 donation requested at the start to help with Meetup fees.
• Kids (who can make it) are welcome, dogs are not.
• Extreme rain will cancel, but we'll trudge through light drizzle. We'll post early Saturday morning if we cancel.
• The last time we did this hike was Feb 2020, and we lucked into seeing large groupings of ladybugs aggregating (dormant, wintering). We're back in this season, so we might see them again1