Not to mention a fantastic place to hike.
"Once you're on the mountain, you learn to love it by hiking it," said Walters.
She is a board member of Save Mount Diablo, which was formed 35 years ago by people who loved the mountain and feared the development creeping up hillsides.
Executive Director Ron Brown said the 50 percent figure was arrived at by figuring in the acreage of Mount Diablo and the rolling hills leading up to it.
"Particularly on the eastern and southern sides of the mountain, when people look up, it looks like a preserved park land," he said. "But it is still owned by private landowners, in many cases grazing cattle."
"When we begin to have more and more development on the fringes of natural lands, we begin to cause wildlife to reshape how they shape their lives," he explained. Even a single large house introduces new elements to the natural habitat, such as fencing and domesticated animals.
"We work with everything from large scale multiple home developments as well as individual homes about design consideration and siting," Brown said. "We respect individuals' property rights; we recognize that people need places to live."
"A huge home interrupts wildlife corridors," Walters noted. "It doesn't work to have an 'island mountain.' Wildlife need large areas of land in which to migrate or we're not going to have bobcats and mountain lions."
Mount Diablo is famous for its views, which can reach 200 miles on a clear day. Save Mount Diablo worries about the view from the Valley, looking up at the mountain.
When the organization was formed in 1971, only 6,788 acres were preserved in the state park at the top. Today, 90,000 acres are protected in 29 parks, open spaces and preserves.
The group was started by Mary Bowerman and Art Bonwell.
Bowerman was attending UC Berkeley in 1930 when she was assigned Mount Diablo as a project for her master's thesis. She began hiking the mountain becoming acquainted with its many facets, and photographing and cataloguing all she found. She had the vision and Bonwell was the organizer, Walters said.
"She had never been on the mountain, and from that project, she became a lifelong advocate," said Walters. "She hiked all over the mountain."
"She was a botany student and she went to (her advisor) and said, 'This is too big for a masters. This is going to be a Ph.D.,' and he agreed," said Walters.
Bowerman's resulting study, "The Flowering Plants and Ferns of Mount Diablo, California," is still the definitive work, said Walters. Bowerman is often quoted: "My dream is that the whole of Mount Diablo, including its foothills, will remain open space ... that the visual and natural integrity will be sustained."
Bowerman died last year at the age of 97.
Co-founder Bonwell, who was an engineer with Dupont, grew up in Indiana and moved here in 1956.
"I was young enough then to ride a bicycle all around and I started a bicycle club," said Bonwell. "We got to be quite active, around Northern California and into Canada. We went over the Sierra Nevadas several times."
He became chairman of the local Sierra Club and the Contra Costa Park Council.
"Mary Bowerman came to our monthly meetings, of both groups, and told us of the wonders of Mount Diablo," recalled Bonwell. "Apparently neither of the groups were being successful in preserving Mount Diablo. I left the Sierra Club and decided we needed another interest group."
"We've been going for 35 years. We have a very popular cause, very much popular not only with the state park but East Bay Regional Park District and local politicians," he added.
Bonwell is still hiking the trails at age 79.
Another of the original founders was Bob Doyle, a pupil at Concord High School in 1971, who came to the early meetings as a student representing Save America's National Environment. He's still involved .
Mount Diablo provides habitat for more than 100 species of animals and 650 species of plants; 12 species of endangered animals and plants have been identified. Just last year, a species of buckwheat was discovered after last being seen in 1936 by Mary Bowerman. Fifteen plants were found on the mountain and more are being propagated at UC Berkeley Botanical Garden.
Seth Adams, director of Land Programs, was the first staff member, hired in 1988. He moved to this area to attend UC Berkeley in 1981 when environmentalists were fighting the Peripheral Canal, proposed to deliver water from the Sacramento River to pumping plants in Southern California.
"There was always a pull between academia and environmentalism," Adams said. "I do have the perfect job - everything from restoring endangered birds to propagating endangered plants to the political stuff, like creating urban limit lines."
His favorite part of the mountain depends on the season: In the spring, he enjoys the waterfalls on the north side. He might go to the 3,849-foot summit on a day when the views are clear.
"The coldest winter day after a big storm is best for the longest views," he said. He estimates that 95 percent of visitors begin by going to the top and enjoying the views.
He noted that 35 years ago none of the trails existed. In 1994, Save Mount Diablo was proud to complete the 30-mile Diablo Trail. Now it is publishing a map of its 60-mile Diablo Grand Loop, which only has two small gaps left to acquire.
Some El Pintado Road residents asked Save Mount Diablo to help last year when the Town of Danville was considering cutting down an oak tree close to the road and it sent a representative to a council meeting. But it did not get involved in maintaining the old Danville Oak on Diablo Road because, Adams said, enough people rallied for its preservation.
"Danville is pretty progressive compared to, say, Antioch," he said. "The big battle is in eastern Contra Costa County and Alameda."
"We're responding to more than two dozen development projects," he said. "We respond to every one of them, whether it's David Duffield's house or 1,800 units in Pittsburg. Lots of times we stop things. We come to compromises where we can preserve a significant amount of land. Blackhawk was the first one."
When Ken Behring purchased the 4,200 acres climbing up the southeast side of Mount Diablo in 1974, he proposed donating 100 acres to Mt. Diablo State Park and developing the remainder into Blackhawk. With the intervention of Save Mount Diablo, the 100 acres was negotiated to 2,100 acres, the largest single donation ever to a state park.
"We've preserved thousands of acres through developer dedications at no cost to the public, and thousands more through mitigation," Adams said. "If a development affects an endangered species, they have to buy land someplace else; we'll help with that."
"Now we go all the way out to Byron and Livermore," he said. "Mount Diablo is the head of the Diablo Range but we don't want to get cut off at the Altamont Pass."
The group is now focusing on the Tassajara Valley, including a proposal to build the 200-acre Creekside Memorial Park Cemetery one mile south of Finley Road.
"There is a scoping hearing on it Feb. 5," Adams said, noting the project would affect a variety of endangered species with its series of lawns and lakes.
He also said Save Mount Diablo is responding to each proposal for a mansion in the Tassajara Valley, explaining that even generous divisions today - such as 1,000 acres into 10 sites - can later be divided again, which is referred to as "stacked subdivision."
"Sometimes we propose to cluster things. We want to place a scenic easement so no further subdivision can take place," he said. "We try to help landowners, when we can, to focus on what's important."
Save Mount Diablo works closely with East Bay Regional Park District and other organizations.
"Having a variety of agencies works very well," said Adams. "We have a variety of managers to choose from so we can weather our funding problems better than some places. When the state is broke, the Regional Park District isn't, necessarily."
Save Mount Diablo needs volunteers for everything from monetary donations to fence building to helping plan and work at its events. The group jumps on new projects even before they are on the planning boards. It compromises in such a way that it gets results, juggling time, money and opportunity with various projects.
The year 2005 saw the culmination of working on the 39-unit Humphrey Ranch project on Stone Valley Road near Monte Vista High School. Save Mount Diablo was able to preserve 62 out of 100 acres, including the upper elevations and big oaks, as well as receive funding to preserve an additional 193 acres.
In 2006, the group protected 473 acres, including seven miles of new trails, and responded to 21 development proposals. It has just completed fundraising for the Mangini Ranch project, which went into escrow Jan. 8; the 207-acre ranch, adjacent to Lime Ridge Open Space, cost $1.47 million.
Save Mount Diablo also works to preserve cherished family property and insure descendents receive fair value in any transaction. For example, the 17 acres remaining of the Young family ranch drops from 1,420 feet with beautiful views, to a mossy, fern-filled canyon. From its founding, Save Mount Diablo had its eye on this prime property but the owners did not want to sell.
When the four offspring inherited it, two of the sisters wanted to see the property preserved but another sister and their brother wanted to sell. The terrain was such that only a few houses could be built, but it was the nightmare of Save Mount Diablo - those homes would have been built halfway up the mountain and right on top of meadow and rare plants. In the end, two of the sisters donated their land, and Save Mount Diablo purchased the remaining portion from the other two. This is why the group needs donations, for when it must make outright purchases.
Save Mount Diablo educates people about the mountain; works to save it, piece by piece; and celebrates it.
A few years ago, after enjoying a one-day hike in Castle Rock Park, Sharon Walters signed up for Four Days Diablo, a feast of hikes led by Seth Adams. Participants became intimately acquainted with the mountain by hiking all day, then enjoying catered gourmet dinners each evening.
"It was absolutely a transformative experience," said Walters, who said each day they hiked about seven miles. "Seth is talking the whole time, walking backwards."
Walters, who has been a librarian at St. Mary's College for 22 years, is earning her master's degree at the college; her thesis is an oral history project on the founding of Save Mount Diablo for which she interviewed Bowerman, Bonwell, Doyle and others.
"The most important thing I learned from them is what a difference just a few committed individuals can make," she said.
She noted that many people who have lived here for years have not hiked on Mount Diablo, perhaps because it can look too forbidding.
"When you get on the mountain and hike it - the single trails and the waterfalls - it is such an amazing mountain," she said. Her first glimpse of it when she's been away, whether from the north or west, always gives her the sense of coming home, she added.
When Walters works at events at the Save Mount Diablo booth, lots of people will stop to talk.
"It's such a great name, Save Mount Diablo," she said. "People will say, 'What's wrong with the mountain?' Because they assume it's all protected."
Only 50 percent.
Types of membership
All members of Save Mount Diablo receive its newsletter with special events, hikes and volunteer opportunities, and the larger donors receive additional benefits.
* Friend - $35
* Trail Blazer - $50
* Diablo Donor - $100
* Mountain Saver - $250
* Peak Guardian - $500
* Summit Club $1,000
Mail memberships to Save Mount Diablo; 1901 Olympic Blvd., Suite 220; Walnut Creek 94596. Donations can be made online at www.savemountdiablo.org or call 947-3535 to contribute with a credit card. For more information call or e-mail firstname.lastname@example.org.