View of rolling golden field and oak trees

Hawthorns Area Plan

Hawthorns Property at Windy Hill Open Space Preserve. By Midpen staff.

The 79-acre Hawthorns area of Windy Hill Open Space Preserve was protected from development when it was gifted to the Midpeninsula Regional Open Space District in 2011. Since then, staff have been working to restore native grasslands, improve community wildland fire safety and protect historic features on the property. A multiyear public process began in 2021 to explore the feasibility of introducing ecologically sensitive public access to the undeveloped portion of the property.

Hawthorns Area Map Updated 5252022


Fieldwork at the Hawthorns Area 

Midpen is conducting ongoing fieldwork and technical studies at the Hawthorns Area to document existing property conditions. Fieldwork may entail survey equipment, vehicles, and personnel within or around the Hawthorns Area. These activities will not result in any immediate improvements but will be used to inform future discussions regarding the location of public access facilities (such as parking areas and trails) within the Hawthorns Area. Please submit questions or inquiries using the comment card available below on this webpage.

There will be multiple opportunities throughout development of the Hawthorns Area Plan for public input. To stay informed, please sign up using the comment card below to receive updates. Additional information will be provided on this webpage as the project proceeds.

Hawthorns Area Plan Q&A

As a part of the Hawthorns Area Planning process, Midpen has collected many questions during our public engagement process. Click below to read the answers to these questions and to learn more about the Hawthorns project. 

Icon of shaking hands with a mountain in the background.
Land Preservation
Natural Resources Protection and Restoration
Natural Resources
Public Access, Education, and Outreach
Public Access
illustration of a bird in flight next to the letters MAA
Measure AA

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Hawthorns Area Virtual Site Tour

Join Midpen staff for a virtual tour of the Hawthorns Area of Windy Hill Open Space Preserve, a 79-acre property located in the Town of Portola Valley. Although the Hawthorns Area is currently closed to the public, Midpen has initiated a planning process to open this to the public. Learn more about this beautiful landscape!


The Hawthorns Area includes rolling grassland, oak woodland and year-round flows in Los Trancos Creek that support a diverse community of native plants and wildlife. To protect the natural environment, Midpen removed debris and old vehicles from the property. Midpen staff also partnered with Grassroots Ecology to restore the property's native grasslands, including carefully timed mowing to reduce the spread of non-native yellow star thistle and removal of non-native, highly flammable French broom. 

Working closely with the Woodside Fire Protection District fire marshal, Midpen also completed significant vegetation management on the property to improve community wildland fire safety, including creating a new shaded fuel break, emergency vehicle staging area and disked fire lines. 

Hawthorns Historic Complex

The property was originally developed in the late 1880s as a summer estate. For more information, please visit the Hawthorns Historic Complex page

Hawthorns House 1893
Hawthorns House - 1893, front (north) elevation
Funded by Measure AA 2014 Open Space Bond

Funded by Measure AA

This project is supported by Measure AA, a 30-year, $300 million bond passed by local voters in 2014 to support Midpen’s community-created Vision Plan top 25 priority projects.

Here is the tentative schedule for developing the Hawthorns Area Plan: 

2021-2022Develop vision and goals for the Hawthorns Area 
2022-2024 Prepare Hawthorns Area Plan 
 2024-2025Conduct environmental review per CEQA
2025Hawthorns Area Plan approval and permitting