Bob Nunn donates “Nunn-Paulsen Inholding” in memory of his father, Ron

“when he could look and see Mount Diablo, he knew he was home”

New law to expedite land acquisitions for state parks

By Laura Kindsvater, Senior Communications Manager, Save Mount Diablo

MOUNT DIABLO, CA— One of Mount Diablo’s last privately owned inholdings, rugged and biodiverse, is now permanently protected from development.

On December 2, 2025, Bob Nunn generously donated five gorgeous acres (known as the “Nunn-Paulsen inholding”), surrounded on four sides by Mount Diablo State Park, to Save Mount Diablo in memory of his late father, Ron Nunn, who passed away in August.

The project has taken just over three months from concept to close of escrow.

This incredible gift will bring us one step closer to making the mountain whole and protected for current and future generations.

Protecting inholdings like this is critical to maintaining the integrity of Mount Diablo and Mount Diablo State Park.

These privately held parcels have the potential to disrupt and threaten conservation efforts in the surrounding park if the inholdings were to be developed or poorly taken care of.

“On behalf of Save Mount Diablo, I thank Bob Nunn for his generous donation of the strategic Nunn-Paulsen property to our organization in honor of his father, Ron Nunn,” said Ted Clement, Save Mount Diablo’s Executive Director.

“This property is on the slopes of Mount Diablo, and is an inholding surrounded on all sides by Mount Diablo State Park. Privately owned inholdings within public parks are major land acquisition priorities for Save Mount Diablo, so we are deeply grateful that this year our wonderful supporters enabled us to complete two inholding acquisitions within Mount Diablo State Park, the ‘Balcerzak inholding’ and now the ‘Nunn-Paulsen inholding.’

“We look forward to working with our good partner California State Parks so that we can eventually transfer these inholdings to them with the assistance of a new law we helped champion to make such acquisitions by state parks easier.”

New Law to Expedite Land Acquisitions for State Parks

We were delighted when Senate Bill 630 (SB 630) was signed into law on October 13th of this year as a result of persistent efforts from us and a dedicated working group of conservation organizations that we helped start last year.

For nearly 20 years, Mount Diablo State Park was unable to add any new land because of the onerous requirement that California State Parks gain approval from other agencies for even minor acquisitions, along with other issues.

The new law will expedite qualifying land acquisitions for California State Parks by allowing the addition of lands, with acquisition costs of $1 million or less, to existing state parks without the need for multiple agency approvals.

With this streamlined process, we are hopeful that inholdings and adjacent lands will now be more easily added to Mount Diablo State Park.

Thankfully, this year, Save Mount Diablo completed the purchase of the 10-acre Balcerzak inholding within Mount Diablo State Park on September 2nd by paying off the $537,500 mortgage so that our organization now owns the property free and clear.

Acquiring and protecting inholdings like the Nunn-Paulsen and Balcerzak inholdings are major accomplishments in our ongoing mission to save Mount Diablo and its sustaining wild lands.

The Nunn Family and Save Mount Diablo

For many years, Save Mount Diablo has deeply appreciated the partnership and support of the Nunn family. The Nunns have deep agricultural roots in Brentwood going back to the 1880s.

Fifth- and sixth-generation Brentwood farmers, they’ve also been involved in development of some of their lands into communities like the retirement community Summerset, and oil and gas, while reinvesting in other agricultural areas.

Responsible land management has always been a key practice of Three Nunns Farm, which is still a thriving family enterprise today.

With Blackhawk Development Company, the Nunns have been involved in many development-conservation projects, like Trilogy at the Vineyards on the remnant of the Cowell Ranch, where 90 percent of the land became a new state park and 10 percent was developed.

The Nunn family has been a major factor in Brentwood’s success.

Bob Nunn has also been a longtime friend and supporter of Save Mount Diablo. On August 20th, he offered to donate the Nunn-Paulsen inholding to Save Mount Diablo.

In the early 1990s, Bob was looking for a place to live, and his dad, Ron Nunn, knew a landowner, Dr. Warren Wise, who owned a property near the corner of Marsh Creek Road and Morgan Territory Road, where Save Mount Diablo made its first acquisition in 1976.

Ron Nunn and Dr. Wise both attended the University of the Pacific in Stockton. On the slopes off North Peak, the Wise property had been on our acquisition lists from the first list in 1972.

Bob called us and said, “There’s this property, it’s 83 acres with an old house I’m going to upgrade, how about I keep five acres and sell you the rest.”

Save Mount Diablo was able to acquire and add the property we named “Three Springs” to Mount Diablo State Park in 1992 thanks to the deal with Bob Nunn. He later served as a member of Save Mount Diablo’s Board of Directors for a time.

His recent thoughtful donation of the Nunn-Paulsen inholding is yet another way the Nunns have helped protect the mountain.

“This donation is being made in memory of my father Ron Nunn, who passed at 92 years of age on August 8, 2025. Although my father had many stories to tell, one that always stuck with me and that I also share is when he could look and see Mount Diablo, he knew he was home,” Bob explained, showing how the mountain means a lot to those of us who live in the Mount Diablo area and connects us.

Generosity and gratitude are the fabric of the land conservation community. During challenging times, donations like this are more important than ever. They help protect our natural foundation and quality of life, while also inspiring us.

As a pillar of the early Brentwood community, Ron Nunn was also a longtime supporter of the East Contra Costa Historical Society, working together to preserve Brentwood’s agricultural roots.

The Nunns placed agricultural conservation easements on some properties to permanently protect the farmlands from future development.

In 2015, the Nunns made a landmark deal with the East Bay Regional Park District to sell 646 acres of Nunn family farmland near Knightsen.

This transaction, in partnership with the East Contra Costa County Habitat Conservancy, allowed the East Bay Regional Park District to restore crucial Delta tidal and freshwater wetlands in the area.

A Biodiversity Gem

The Nunn-Paulsen property is a compact and biologically diverse gem. This Marsh Creek watershed location includes two ephemeral streams, harboring a huge variety of plant life on its steep, rocky slopes.

The property contains blue oak and live oak woodland and oak savanna habitat. California red-legged frog and Alameda whipsnake are special status species that are likely to be present on the property. They’re confirmed on the neighboring Three Springs property.

The serpentine rock on the Nunn-Paulsen land provides excellent growing conditions for rare plant species.

A hike there is both adventurous and intimate. In winter especially, the dramatic shape of the land means that storms and seasonal rain bring small waterfalls.

In addition to its important location on the slopes of Mount Diablo, the Nunn-Paulsen inholding is also strategically located in a wildlife corridor between Mount Diablo State Park and Black Diamond Mines Regional Preserve.

An Ambitious Conservation Vision and Growing Success, Piece by Piece

Save Mount Diablo has acquired and protected many important properties in the area near the recently acquired Nunn-Paulsen inholding.

In 1976, Save Mount Diablo’s very first acquisition was in this same area: The Corner Piece. The Corner Piece is 117 acres of blue oak woodland at the corner of Morgan Territory and Marsh Creek roads.

Soon after Save Mount Diablo acquired The Corner Piece, Mount Diablo State Park protected North Peak, allowing the creation of the Olympia Trail to Mount Olympia.

In 1992, Save Mount Diablo acquired and transferred the Three Springs property to California State Parks for inclusion in Mount Diablo State Park.

In 1994, Save Mount Diablo’s community-funded purchase of the 333-acre Chaparral Spring parcel turned it into a thriving, protected oasis home to wildlife like the golden eagle and endemics like the Mount Diablo globe lily—and a critical step in creating a Mount Diablo State Park wildlife and recreational corridor.

Later we transferred the property to East Bay Regional Park District. Save Mount Diablo, the park district, and the East Contra Costa County Habitat Conservancy have since protected several thousand acres to connect the two parks.

Save Mount Diablo protected the botanical diversity of Young Canyon by preserving this property in 2006 in what we call the “Missing Mile” on the slopes of North Peak.

It nurtures well over a hundred species of flowers, including five California endemics, because it’s crossed by the only band of serpentine on Mount Diablo.

The landscape of Young Canyon includes a 1,420-foot knoll, a mossy, fern-filled stream canyon, and a rocky meadow of wildflowers where you’ll often see hawks and turkey vultures riding the constant breeze.

The next year, Irish Canyon was Save Mount Diablo’s breakthrough purchase, stopping development speculation and expanding the Mount Diablo–Black Diamond wildlife corridor.

This land is a vital 320-acre watershed property with over 297 species and a permanent pond.

In 2022, Save Mount Diablo successfully acquired a very important conservation easement from the Concord Mt. Diablo Trail Ride Association.

Save Mount Diablo’s conservation easement permanently protected from development 154 acres that are a prominent part of the Mount Diablo high peaks ecosystem, and another step in filling in the North Peak “Missing Mile.”

Krane Pond is one of Mount Diablo’s largest water sources, drawing all sorts of creatures, like bobcats, red-legged frogs, and migrating birds—so Krane Pond’s acquisition and protection by Save Mount Diablo in 2023 was vital to local habitat conservation.

It was another step in filling in the “Missing Mile.”

The Nunn-Paulsen property had been one of the few remaining privately owned inholdings not yet protected on Mount Diablo, and that changed on December 2nd with Save Mount Diablo’s successful acquisition of the land, thanks to Bob Nunn.

Holiday Gift, Gratitude, and What’s Next?

Bob Nunn’s generous donation of the strategic Nunn-Paulsen inholding on the slopes of Mount Diablo to Save Mount Diablo is a wonderful holiday gift for the mountain and our communities, including the people, flora, and fauna of the area.

Our stewardship team is excited to begin caring for the property.

At Save Mount Diablo, we are grateful for our supporters and the progress they have helped our organization make this year in successfully advancing our land conservation mission, including helping advance acquisition priorities for California State Parks.

The new law we helped champion (SB 630) that will streamline the acquisition process for California State Parks, and our completing the Balcerzak and Nunn-Paulsen inholding acquisitions, are major accomplishments.

SB 630 covers many properties our organization has been working to convey to California State Parks for addition to Mount Diablo State Park (the 101-acre CEMEX parcel, parts of Curry Canyon Ranch, the Balcerzak inholding, the Nunn-Paulsen inholding, the Viera North Peak property, etc.).

We look forward to working with California State Parks in the new year to start utilizing the new law to add these lands to Mount Diablo State Park.

For more information about Save Mount Diablo visit savemountdiablo.org.