Winter, spring meet on Mount Diablo
In one turn of the head this past week, you could see spring and winter along a 10-mile swath across the flank of Mount Diablo.
From a lookout at Buckeye Hill, you could see in the valley below a carpet of bright yellow blooming mustard providing early-spring nectar for bees and other pollinators. Beyond, in the Pine Creek watershed and slopes leading up past Castle Rocks, the hills were aglow in greens, with the oaks leafing out in fresh lime green buds.
It looked like a magical spring.
Yet just above that, high on the 3,849-foot mountain, the rare snow of last week contrasted against a cobaltblue sky. And that was before the big storm in late week took hold and buried the mountain in a cloud.
It looked like a magical winter.
As March arrived, spring and winter merged into one across many Bay Area and Northern California landscapes. In Mount Diablo’s vast footprint, the best place to see the phenomenon is a network of parks and open space in the foothills just outside Walnut Creek.
Old Borges Ranch
The best starting point is a staging area called Old Borges Ranch, part of Shell Ridge Open Space and operated by the city of Walnut Creek. The trailhead provides access to Shell Ridge and other trail-connected parklands, including Diablo Foothills Regional Park, Castle Rock Recreation Area and Mount Diablo State Park.
The trail system is an example for park agencies across America of how to do it right. A vast network of roads, routes and trails connects a series of parklands, despite each being managed by a different agency.
The Old Borges Ranch has a restroom and drinking water, along with an interpretive center and a ranger station. At the southern end is the starting point — the Borges Ranch Trail, a service road — which, in just a few minutes, leads to the Briones-to-Mount Diablo Trail.
Turn left (south) and your adventure begins. The Briones-to-Mount Diablo quickly exits the open space preserve and enters Diablo Foothills Regional Park on the flank of Shell Ridge. In just over a quarter-mile, you will reach a second junction — Buckeye Ravine Trail.
Turn left. After a short distance, before descending too far, break off to the right and trek a short way up the flank of Shell Ridge.
This is the payoff. You can see across the Pine Creek watershed, beyond to Castle Rocks, the series of rock outcrops and spires, and up the slopes of Mount Diablo. Many paths, one truth
From here, you can choose all kinds of routes to complete your day. The best is to descend down the Buckeye Ravine Trail to Pine Creek Canyon. Depending on your level of ambition, you can then turn left to turn the trek into a 2.6-mile loop (there are many routes available, including Diablo Scenic Trail).
Many will want much more than that. And here, you can get it. Trails and routes are available for mountain bikers and horses, as well as for easy walks and hikes.
These are the home parks for field scout Brian Murphy, a master landscape photographer, who helped introduce this area to me.
For years, when I flew into the Bay Area, often over Concord to Newark to Palo Alto, my route often took me right over Shell Ridge, Castle Rocks and nearby China Wall. Like so many, I was fascinated with the monolithic rock structures, and it was Murphy who shared his favorite trails to see them.
Murphy, along with East Bay Park naturalist Ned MacKay, showed me how to find marine fossils embedded in the sandstone from the time when this area was at the bottom of the ocean.
Turns out you get more than that now. You can get winter and spring, all at once.