Marin County supervisors have accepted the donation of a roughly 7-acre hilltop known as Sky Ranch Knoll, adding it to the 107-acre Bald Hill Preserve and closing out a conservation campaign that began 45 years ago. The parcel straddles the border between Fairfax and San Anselmo and had been the site of a now-shuttered equestrian facility before a new owner decided to sell.
The Marin County Open Space District Board of Directors is scheduled to formally vote on the donation agreement on Tuesday, with escrow expected to close in September, according to Marin County. As reported by the Marin Independent Journal, the effort traces back to 1981, when the Town of San Anselmo created the San Anselmo Open Space Committee, which made preserving Bald Hill and the surrounding Sky Ranch ridgelines the centerpiece of a master plan later folded into the town's general plan.
Jonathan Braun worked on the Sky Ranch preservation effort for 35 years, per the Independent Journal's reporting, and Marin Open Space Trust had actually wanted to purchase Sky Ranch Knoll back in 2015 when it acquired three other parcels totaling 16.2 acres known collectively as Sky Ranch. That earlier deal saw the nonprofit transfer the land to Marin County for $630,000, funded through $330,000 in local Measure A tax dollars and a $300,000 grant from the California State Coastal Conservancy, according to the San Anselmo-Fairfax Patch.
A Bequest Closes the Final Gap
The equestrian community that once operated at Sky Ranch Knoll was unable to raise money to replace its deteriorating buildings, and the facility was forced to close because the structures had fallen into disrepair, the Independent Journal reports. The property later went through bankruptcy before a new owner emerged who was interested in selling, setting up the final piece of the decades-long puzzle.
That final piece came together thanks to Maureen Groper, who died in 2024 and left $1 million to the San Anselmo Open Space Committee. The committee committed $800,000 of that bequest to the Sky Ranch Knoll purchase, and Marin Open Space Trust also launched a fundraising campaign targeting $90,000 by mid-June, drawing contributions from the Town of Fairfax, the Tamalpais Conservation Club, and roughly 60 private donors, according to the Town of Fairfax. The property owner asked that the final purchase price, which was based on an appraisal, not be disclosed.
Landslide Risk and a Debris Barrier
Before completing the deal, Marin Open Space Trust commissioned a geotechnical report as part of its due diligence. The report identified an area on the property where landslides had repeatedly occurred and found that debris could mobilize during severe storm events or seismic shaking, traveling downslope through a narrow channel — though it also found relatively low overall risk of movement or property damage, per the Independent Journal's account.
To address the localized hazard, Marin Open Space Trust gave the Marin County Open Space District $100,000 to make Sky Ranch safer. That money will fund construction of an attenuation barrier, described in the reporting as something like a big volleyball net designed to catch slide overburden before it reaches areas below.
New Views, New Trail Miles
Once added, Sky Ranch Knoll will be managed by the Marin County Open Space District and will be linked to Bald Hill by trail connections running through adjoining Marin Municipal Water District lands. The addition extends public trail access by roughly a quarter-mile and opens a new high-elevation viewpoint with sightlines to San Pablo Bay, Mount Tamalpais, Bald Hill, and San Anselmo, according to Marin County.
Supervisor Brian Colbert, who represents the area near the knoll, said Sky Ranch Knoll is the final piece of a conservation vision decades in the making. The acquisition marks the sixth purchase Marin Open Space Trust has completed toward preserving Bald Hill and Sky Ranch, following the district's earliest acquisitions in the area back in 1994, and it achieves what county officials describe as an unbroken open space greenbelt running from the top of Bald Hill to Sky Ranch.
Part of a Broader Marin Land Rush
The Sky Ranch Knoll donation lands just weeks after another major Marin conservation deal: in July, county supervisors approved accepting the 161-acre summit of King Mountain near Larkspur, purchased by Marin Open Space Trust with funding from the Shelby Cullom Davis Charitable Fund, as detailed by SFGATE. Hoodline previously reported on that Larkspur summit deal before the Sky Ranch Knoll transaction came together.
Before Sky Ranch Knoll, the preserve's largest recent expansion came in 2023, when Marin Open Space Trust facilitated the $3.95 million acquisition of the 60-acre treeless summit of Bald Hill, growing the preserve from 46 to 106 acres, according to the San Anselmo Open Space Committee. The Bald Hill Open Space Preserve itself dates to a 1993 purchase of 17 acres in San Anselmo, followed by a 1996 purchase of the 5-acre Quilici property for $105,000, split evenly among the town, the county, and the Marin Community Foundation.
Sky Ranch parcels were identified as high-priority conservation targets because of their ecological significance, and protecting the area connects Bald Hill Preserve to a contiguous corridor of more than 100,000 acres of public lands stretching west to Point Reyes National Seashore and south to the Golden Gate National Recreation Area, per the Patch report. Still, the San Anselmo Open Space Committee estimates that nearly 30% of local lands designated for open space have been lost to development since 1981, even accounting for wins like the Bald Hill Ridge and the 22-acre Hawthorne Canyon. Much of the funding behind these deals continues to flow through Marin County's Measure A, a voter-approved quarter-cent sales tax dedicated to parks, open space, and farmland preservation that provides matching funds for land trust transactions.
