The mountain range that defines Walnut Creek's eastern skyline is now an official California conservation priority.
The state Senate voted 33-0 on Thursday, Aug. 13, to approve Assembly Concurrent Resolution 107, recognizing the Diablo Range as critical to California's goal of conserving 30 percent of its lands and coastal waters by 2030. The Assembly had already passed the measure 74-0 on Sept. 13, 2025.
Assemblymember Rebecca Bauer-Kahan authored the resolution, and Walnut Creek-based nonprofit Save Mount Diablo sponsored it. Senator Laird introduced ACR 107 on the Senate floor before the final vote.
"The California legislature's historic approval of our resolution has just given much needed visibility, attention, and momentum to protecting the previously little-known, yet hugely important, Diablo Range," Save Mount Diablo executive director Ted Clement said in a statement Thursday.
What the designation means
The Diablo Range stretches more than 200 miles across 12 counties and encompasses over 4 million acres of largely intact, undeveloped land. Mount Diablo sits at the range's northern end in Contra Costa County. Less than 30 percent of the range is currently conserved.
ACR 107 is a concurrent resolution, not a statute. It carries no legal mandate. No dedicated funding comes with it. But it gives the range official state recognition and could build momentum for future conservation legislation and dollars.
The resolution ties directly to California's 30x30 climate initiative. At the Second Annual Diablo Range Convening in June, Dr. Jennifer Norris, executive director of California's Wildlife Conservation Board, said at least 1 million acres of the Diablo Range could help the state close a 4.8-million-acre gap it still needs to meet the 2030 target.
Local connections
More than 10 million people live in communities surrounding the Diablo Range, and Walnut Creek residents are among the closest. The range is home to hundreds of rare and endangered species, including the California condor and the blunt-nosed leopard lizard.
Save Mount Diablo, headquartered in Walnut Creek, has opened more than seven miles of new trails to the public in recent years and is adding two miles at Magee Preserve in Danville. The organization reported $6.82 million in revenue for its 2025-2026 fiscal year and recently received a $2.15 million grant from the Wildlife Conservation Board for habitat work in eastern Contra Costa County.
A 160-acre portion of Curry Canyon Ranch near Mount Diablo is on the verge of transfer to the East Contra Costa County Habitat Conservancy, with a perpetual conservation easement on an adjacent 155 acres.
The resolution's path took nearly a year. The Assembly Committee on Water, Parks and Wildlife approved it Sept. 10, 2025; the full Assembly followed Sept. 13, 2025; the Senate Natural Resources and Water Committee cleared it June 9, 2026; and the full Senate gave final approval Aug. 13.
What's ahead
No specific follow-up legislation has been announced, but Save Mount Diablo has said the designation is a stepping stone toward future conservation funding for the range. The June convening drew more than 130 people from nearly 70 organizations, including California tribes, land trusts, agencies and landowners, to coordinate next steps.
Walnut Creek residents who hike Shell Ridge, Lime Ridge or the trails around Mount Diablo State Park are walking the northern tip of the range that Sacramento just recognized.
