If you live in Diablo, you already know the trails. Mitchell Canyon on a weekday morning. The Black Point Trail when you want elevation and a reason to push. The way spring turns the lower slopes electric with globe lilies and Ithuriel's spear before the hills go gold. The park has been the backyard for as long as most residents can remember.
What most residents don't know is that the park has been artificially frozen at its existing boundaries for nearly two decades — not because there was no land to add, but because the approval process required to add it had become effectively impossible to navigate. Properties were identified, land trusts made deals, and acquisitions waited. The queue of land ready to join the park grew longer. Nothing moved.
That changed in January 2026. And for people who live a few minutes from the Mitchell Canyon trailhead, the consequences are already showing up on the ground.
The Law That Unlocked It
The logjam had a specific cause. Under the prior framework, adding land to an existing California state park required a multi-agency approval process that, in practice, made most acquisitions grind to a halt. State budget pressures in 2008 and 2011, multiple reorganizations within California State Parks, and a process that could stall on a single agency's calendar — all of it combined to keep Mount Diablo's footprint unchanged for close to 20 years despite willing donors and ready parcels.
Senate Bill 630 changed the rules. The law, which Save Mount Diablo helped pass and which took effect in January 2026, created a streamlined approval path for land additions with an acquisition cost under $1 million. For the first time, California State Parks had a mechanism to actually move on the properties that had been waiting. The agency moved quickly. Within months of the law taking effect, the first acquisitions were underway.
The First Property In: Black Point Trail Gets Permanently Protected
This spring, Save Mount Diablo is celebrating what it's calling "the long-awaited addition of the 101-acre CEMEX property to Mount Diablo State Park." The parcel sits above Mitchell Canyon, adjacent to the existing park boundary, and features chaparral, oak woodland, and canyon slopes on the flanks of Mount Zion.
The detail that matters most to hikers: a section of the Black Point Trail runs directly through the property. The full Black Point Summit Loop from Mitchell Canyon covers 4.9 miles with 1,151 feet of elevation gain — moderate terrain that takes most people between two and three hours. That trail section was, until now, running through land that could have been developed or closed to public access. The CEMEX donation, which the company first announced in 2022 after six years of negotiations with Save Mount Diablo, is now completing its formal transfer to state ownership.
Mitchell Canyon itself is one of Mount Diablo's most-used entry points, known to birders for its spring and summer habitat and to botanists for endemic species found nowhere else on earth. The small visitor center near the trailhead and the adjacent native plant garden serve as the de facto gateway for most first-time and casual visitors. Adding 101 acres of adjacent land to this section of the park closes a gap that has existed on the map for years.
Ted Clement, Save Mount Diablo's Executive Director, said the acquisition "will be a great benefit to our local communities including our native flora and fauna."
The Second Deal Already Closed: Curry Canyon Ranch
The CEMEX celebration is the most visible piece of news, but a second, larger transaction closed earlier this year with less fanfare. In February 2026, the California Wildlife Conservation Board approved $2.15 million in state and federal grant funding to support a conservation agreement at Curry Canyon Ranch — land that Save Mount Diablo has owned and managed since 2013. The deal has three components:
- 160 acres conveyed in fee simple to the East Contra Costa County Habitat Conservancy, with plans for eventual transfer to Mount Diablo State Park
- 155 acres placed under a perpetual conservation easement, held by the same Conservancy, guaranteeing no development regardless of future ownership
- Knobcone Point Trail already open to the public under Save Mount Diablo's ownership, providing access now while the formal transfer process continues
Curry Canyon Ranch occupies the southeastern side of the mountain and represents one of the most biodiverse sections of the broader Diablo Range. The conservation easement component is worth understanding clearly: it is permanent. Even if the land never formally transfers to state ownership, the 155 acres it covers cannot be developed. The easement travels with the title forever.
Save Mount Diablo retains ownership of the easement-protected acres and continues to manage the ranch house area for education programs and public events.
What's Still in the Queue
The CEMEX parcel and Curry Canyon Ranch are the first two completions under the new law, but they are not the last. Save Mount Diablo has described several additional properties already in line for transfer to the park, including the Viera-North Peak property and the Balcerzak inholding. A new law creating a streamlined process and a pipeline of identified acquisitions is a different situation than a single transaction. This is an expansion program, not a one-time addition.
For residents who use the park regularly, the practical implication is this: the trail system connected to your neighborhood is going to grow, and the boundaries of what is permanently protected are moving outward.
What This Means If You Live Here
Mount Diablo State Park is a named amenity in nearly every conversation about what makes this area worth living in. What has been harder to articulate is the difference between a fixed amenity and an expanding one. A park that hasn't grown in 20 years is static infrastructure. A park in the middle of its first expansion cycle in two decades, with a legal mechanism in place and multiple properties already in the process, is something different: a living open space with improving access and deepening permanence.
For Diablo residents specifically, the expansions are happening on the trails they already use. Black Point and Mitchell Canyon are not abstract additions to a distant corner of the park. They are the routes people run on Tuesday mornings and take out-of-town guests on Saturday afternoons. The land being added is contiguous and accessible. And the permanence of the conservation easements means that what surrounds the park's edges today will not become something else tomorrow.
Jill Fusari has lived and worked in this area long enough to know that the details shaping a neighborhood's quality of life tend to surface in local news long before they show up in a real estate conversation. If you have questions about what is happening in Diablo or the surrounding communities, she is glad to talk.
