For decades, hikers in Larkspur have walked the flanks of King Mountain while staring up at a fenced-off summit they were not allowed to touch. That is on the verge of changing. A privately held mountaintop parcel just above downtown is poised to become public open space after Marin Open Space Trust snapped up 161 acres with help from a philanthropic foundation. The deal would finally unlock a 32-acre summit that has been off-limits for years. The Marin County Open Space District board is scheduled to weigh the donation on Tuesday, with escrow expected to wrap up in September 2026.
Donation and timeline
According to Marin County, the Shelby Cullom Davis Charitable Fund bankrolled Marin Open Space Trust’s purchase and put up a $2 million stewardship endowment to cover at least a decade of restoration work, invasive-species management and basic upkeep. If the Marin County Open Space District board signs off on the donation and stewardship agreements on Tuesday, Marin Open Space Trust would finish the purchase and turn the property over to the district no later than Sept. 8. County staff say the move would add the summit to the King Mountain Open Space Preserve and keep it from being developed as a single large estate.
A decades-long fight
Neighbors and conservation advocates have been trying to protect this peak since the 1980s, when the King Mountain Open Space Association formed to fend off development plans. The 32-acre summit stayed behind fences and at times carried approvals for a 27,500-square-foot estate. Before Marin Open Space Trust stepped in, the parcel was on the market through Omega Three Trust for $19 million, the San Francisco Chronicle reports. Parks director Chris Chamberlain told the Chronicle that “this is one of the last ridgetops in Marin that had yet to be protected,” and locals have been quick to call the donation a milestone.
How the public will benefit
If the land is transferred to the Marin County Open Space District, the King Mountain preserve would balloon from roughly 108 acres to about 269 acres, and the once-private summit would become part of the public trail system. Hikers would gain 360-degree views of Mount Tam, Tiburon and San Pablo Bay, according to Marin County. The stewardship endowment is earmarked for new signage, trail upgrades and at least ten years of habitat work, which county staff say will help fund invasive-species removal and ongoing maintenance.
How the deal came together
The project moved unusually fast. Representatives of the Shelby Cullom Davis Charitable Fund cold-emailed Marin Open Space Trust chair Bill Long and offered to buy the land and give it to the county, Long told the San Francisco Chronicle. Marin Open Space Trust then negotiated with Omega Three Trust and signed a purchase agreement in April. The foundation financed the acquisition and is set to transfer title to the county once escrow closes.
Trail rules and visitor tips
For now, visitors can still explore the existing 3.5-mile loop trail that wraps around the mid-section of King Mountain. Marin County Parks urges hikers to stick to marked routes, pack plenty of water and plan around limited street parking. There are no restrooms at the preserve, and dogs must follow leash rules on trails and voice-control rules on fire roads, consistent with county guidance.
The Open Space District board meets on Tuesday. If it approves the donation agreement, Marin Open Space Trust would complete the purchase and hand the summit to the county by Sept. 8. For hikers who have spent years circling just below the fence line, that long-teasing peak may finally become a local climb instead of a distant backdrop.
