Save Mount Diablo expands to protect Diablo Range

Save Mount Diablo expands to protect Diablo Range

Save Mount Diablo expands to protect Diablo Range
The view of the Diablo Range from the top of San Benito Mountain, the range’s highest peak. (Stephen Joseph photo)

Save Mount Diablo (SMD) has launched a campaign to connect Mount Diablo to the whole of the Diablo Range, a 150-mile long mountain range and biodiversity refuge that’s next door to millions of people – but that is unfamiliar to most people.

“The Diablo Range is the missing piece of the California conservation map,” says Seth Adams, SMD’s land conservation director. “It’s California’s next great conservation story.”

“Seventy-five percent of the ecologically important area around Mount Diablo has been preserved,” explains Edward “Ted” Sortwell Clement Jr., SMD’s executive director, “while in the full 150-mile range, only 24 percent of the landscape has any protection. We’re going to change that.

“Save Mount Diablo’s first step is defining the range as a whole for the conservation community and the public and educating them about its importance,” Clement adds.

Article in Bay Nature magazine

As part of this campaign, SMD helped sponsor a cover story and supplement about the Diablo Range in Bay Nature magazine, along with the Santa Clara Valley Open Space Authority.

“The Spine of California,” by Bay Nature digital editor Eric Simons, explores the most rugged, plant-rich stretch of California that remains unknown to most residents.

The cover story is the first article ever published specifically about the Diablo Range, and it includes the first published map of the public and protected lands of the Diablo Range.

“Our first effort is to put this place on the map,” notes Adams.

Expanding advocacy area

Save Mount Diablo expands to protect Diablo Range
This map shows the northern Diablo Range, including Save Mount Diablo’s recently expanded area of interest down to the Santa Clara County line. (Map courtesy Save Mount Diablo and Nomad Ecology)

As part of the campaign, SMD recently expanded the geographic area in which it now does its land use advocacy to include the three northern counties of 12 crossed by the Diablo Range.

The organization’s primary acquisition focus remains north of Highway 580 and around the main peaks of Mount Diablo. The organization recently announced two acquisition projects on the main peaks, the 154-acre Trail Ride Association conservation easement on North Peak – for which it needs to raise about $1,040,000 – and the $650,000 Smith Canyon project adjacent to Curry Canyon.

In addition to working in Contra Costa County between Highway 680 and the Byron Highway, SMD now also works in southeastern Alameda and southwestern San Joaquin counties. This area includes an essential, 10-mile-wide wildlife corridor – including the Altamont Pass – that connects Mount Diablo to the rest of the Diablo Range. It also includes one of the most important and vulnerable biodiversity hotspots in California.

“The 150-mile range of mountains from the Carquinez Strait to the oil fields of the southern San Joaquin Valley holds some of the largest remaining wild places in California,” says Simons. “It is a rugged, remote, difficult realm, a biodiversity ark incised by the San Andreas Fault. It is a historic mixing place, where Central Valley Yokuts and coastal Ohlones traded and danced, where California’s ever-more-diverse future residents will seek escape and recreation. And it is nearly unparalleled in ecological significance.”

From the Carquinez Strait to Antelope Valley

The Diablo Range stretches from the Carquinez Strait all the way to the Antelope Valley in Kern County and contains some of the largest remaining unprotected wild places in California. The mountain range is huge, rugged and remote. Bounded by Highway 101 to the west and Highway 5 to the east, the 150-mile long, 40- to 50-mile wide area is a blank spot on the map for the public focused on its outer grassland foothills.

“Five miles in and 500 feet up, oaks and chaparral appear,” Adams says, “and it’s Mount Diablo multiplied.”

The Diablo Range covers 5,400 square miles and has many peaks, some of which are taller than Mount Diablo. The tallest one is San Benito Mountain at 5,241 feet. Mount Diablo measures 3,849 feet.

Key wildlife habitat

Save Mount Diablo expands to protect Diablo Range
Rare plant species grow along the serpentine ecosystems at San Benito Mountain. (Stephen Joseph photo)

The range is extremely important for wildlife, crossed only by two major highways at Altamont and Pacheco passes. It serves as a reservoir of biodiversity, a core habitat for wildlife in California.

Although golden eagle populations are declining in western North America, they’re stable in California because of the Diablo Range. The northern Diablo Range supports the highest density of golden eagles on the planet.

The Diablo Range could also be the source for replenishing the genetic diversity of mountain lion populations in the Santa Cruz Mountains. Tule elk, nearly hunted to extinction in the 1970s, have recovered quickly in the Diablo Range. Bay checkerspot butterflies have their last stronghold along Coyote Ridge just above San Jose. And the Diablo Range offers great habitat for California condors to expand into as they recover from the brink of extinction.

The Diablo Range is threatened by energy development (both alternative and fossil fuel-based energy), suburban sprawl, and proposed dams and reservoirs. Wind turbines endanger golden eagles and other birds. And the Panoche Valley, part of the Diablo Range, now has a 4,800-acre solar farm.

This mountain range contains large swaths of land with serpentine soils, home to rare plant species that don’t grow anywhere else. And some of the soils are “vertic clays,” which also support rare and endemic plant species.

Although the Diablo Range is right next to some large cities, large areas of it have limited to no cell phone coverage, light pollution or major roads – an indication of its habitat connectivity.

For more information, visit or

Photo by Stephen Josephs