Corte Madera · Hidden Valley
Protecting Alta Woods Today. Preserving Our Hillside for Tomorrow.
A community effort to preserve Alta Woods and protect the steep, interconnected hillside that surrounds it.
For decades, neighbors have walked alongside the wooded slopes of Alta Woods — one of Hidden Valley's few remaining undeveloped woodland areas. A proposed access road through this landscape has put its future at risk. The Alta Woods Preservation Group is an all-volunteer neighborhood effort working to preserve Alta Woods as permanent open space.
But Alta Woods does not exist in isolation. It is part of a steep, interconnected hillside where trees and vegetation, drainage, roads, homes and open space are closely linked. What happens on one part of the hillside can potentially affect another.
Our mission is both to preserve Alta Woods and to advocate for thoughtful stewardship of the surrounding hillside — with careful consideration of drainage, slope stability, fire and life safety, vegetation, access, traffic and impacts on neighboring properties.
Why Alta Woods Matters
A place that gives back to the whole community
Alta Woods matters to Hidden Valley — and to Marin's goals for climate resilience, biodiversity, and connected open space.
For Residents
A peaceful place to walk, reflect, and connect with nature.
For Wildlife
A continuous habitat corridor, not fragmented woodland.
For Future Generations
Something that cannot be recreated once it is lost.
For Marin County
An investment in resilience, biodiversity, and community well-being.
Why Now?
What began as an effort to protect Alta Woods has revealed a larger issue.
Alta Woods does not exist in isolation. It is part of a steep hillside above homes and alongside Alta Terrace. Decisions involving tree removal, vegetation clearing, grading, drainage, road construction and development elsewhere on this hillside may have consequences beyond an individual property.
Recent activity adjacent to Alta Woods has reinforced the importance of looking at the hillside as an interconnected system — and ensuring that future decisions fully consider drainage, slope stability, fire and life safety, access, vegetation, and impacts on surrounding residents.
A second access roadway has also been proposed through Alta Woods to serve development at 800 Corte Madera Avenue. The Town Council denied the first proposal in 2025. In 2026 the owners won an SB 9 lot split; access through Alta Woods and hillside development remain unresolved.
Preserving Alta Woods remains at the center of our mission. But protecting Alta Woods also means understanding and advocating for the health, safety and long-term stewardship of the hillside around it.
For decades
800 Corte Madera Ave. is served by its existing driveway.
2025
Town Council denies the proposed roadway.
2026
SB 9 lot split approved; Alta Woods access still unresolved.
August 2026
Significant tree and vegetation removal occurs on the 800 Corte Madera Avenue property adjacent to Alta Woods and Alta Terrace, prompting neighbor questions about Town oversight, applicable processes, and potential implications for drainage, slope conditions, fire and life safety, and the surrounding neighborhood.
Today
Planning continues, and so does community stewardship.
Why the Larger Hillside Matters
What happens on one part of this hillside can affect another.
Tree and vegetation removal, grading, new roads, retaining structures and other significant alterations can potentially change drainage patterns, affect slope conditions and vegetation, and create new fire, safety and access considerations for surrounding residents.
These concerns are particularly important on a steep hillside where homes, roads, vegetation, drainage systems and open space are closely interconnected.
AWPG believes decisions affecting this hillside should be based on careful analysis, transparent public processes and a full understanding of potential impacts on the surrounding neighborhood.
Our Priorities
Three goals that guide our work
Preserve Alta Woods
Protect Alta Woods and the historic paper road from vehicular development and pursue the long-term vision of preserving this special area as neighborhood open space.
Protect the Hillside
Encourage thoughtful stewardship of the surrounding steep hillside, including appropriate consideration of trees and vegetation, drainage, erosion, slope stability and the cumulative effects of significant land alterations.
Safeguard the Neighborhood
Ensure that development decisions appropriately consider fire and life safety, emergency access, traffic, road conditions, drainage and potential impacts on residents and properties above and below the hillside.
Our Mission
The Alta Woods Preservation Group was formed to protect Alta Woods and pursue its long-term preservation as open space.
Through that effort, our mission has grown to include advocacy for thoughtful stewardship of the surrounding hillside and for development decisions that appropriately consider drainage, slope stability, vegetation, fire and life safety, access, traffic and impacts on neighboring properties.
We believe preservation, responsible development and public safety all begin with understanding that this hillside is an interconnected system.
Our Vision
A connected greenbelt for Hidden Valley
The proposed roadway brought neighbors together. Our vision reaches further: a protected woodland pathway, a scenic hillside left intact, and a lasting connection to the open space that defines this neighborhood.
Explore Our Vision- Preserve woodland and open space
- Protect mature trees and wildlife habitat
- Support quiet public enjoyment and stewardship
- Build the partnerships that make conservation last
Support Our Work
The future of Alta Woods will be shaped by the people who show up. We are entirely volunteer-led. Community support helps us participate in planning, get independent expertise, and advance long-term stewardship.
Support Our Work