Project Name
Cascade Trail Bridges
Improving visitor safety and preserving habitat in Cascade Canyon
June 8, 2026
Construction to Begin
Work on the upper Cascade Canyon bridge (bridge 2) and adjacent project elements is expected to occur from August through October 2026.
Work on the lower Cascade Canyon bridge (bridge 1) and adjacent project elements is expected to occur from August through October 2027.
All work is expected to be completed by October 2027.
Project Summary
Cascade Canyon Open Space Preserve is a popular recreational corridor for pedestrians, cyclists, and equestrians traveling in between residential areas of Fairfax and Camp Tamarancho. San Anselmo Creek contains sensitive aquatic habitats that support federally listed steelhead, candidate for federally and state-listed foothill yellow-legged frog, and other native species. Recreational traffic through four existing low-water rock ford creek crossings within the San Anselmo Creek channel puts visitors at risk of injury during high creek flows in the rainy season and can also mobilize fine sediment that could negatively impact downstream steelhead and the upstream passage of young fish into summer rearing habitat. Additionally, foothill yellow-legged frogs in aquatic habitats could potentially incur physical impacts from park visitors using the rock fords. The Marin County Open Space District (MCOSD) has also determined that the High Water Trail is substandard in design and safety.
MCOSD will improve trail safety, visitor access, and enhance habitat protection for aquatic species in San Anselmo Creek by installing two trail bridges (upstream bridge and downstream bridge) and implementing trail improvements to allow multiuse access. The trail improvements will include realignments to access the bridges, new signage and fencing, bicycle speed control features, and a bike rack. The project will also decommission and restore the Highwater Trail along with the Canyon Trail spur that connects to Cascade Fire Road. The trail decommissioning work will eliminate trail redundancy and rehabilitate damaged stream banks.
Objectives
- Provide safe and sustainable year-round access to the Canyon Fire Road and the interior of Cascade Canyon Preserve
- Eliminate the need to ford San Anselmo Creek using the rock fords located within the creek
- Enhance habitat protection for listed species
- Improve trail safety
- Improve visitor access compliant with MCOSD’s Inclusive Access Plan
- Reduce road and trail erosion and sediment delivery to San Anselmo Creek
- Reduce the number of redundant trails and habitat fragmentation in an area rich in sensitive species.
California Environmental Quality Act
MARCH 8, 2022
Comment Period Concluded
The Initial Study/Proposed Mitigated Negative Declaration, prepared to comply with the California Environmental Quality Act (CEQA), was circulated for public review and comment February 16, 2021 through March 19, 2021. One hundred ninety individuals and organizations submitted comments. Prior to releasing a formal response to comments document, MCOSD is working to obtain information needed to address the public comments.
MCOSD commissioned a traffic consultant and installed visitor use cameras for a three-week period in August-September 2019 and a six-week period in March and April 2021. The traffic study analysis is currently underway. Data from that study and visitor use cameras will help inform a response to comments concerning traffic and visitation.
To address comments about habitat restoration, MCOSD has developed a draft habitat restoration plan, which is being finalized.
MARCH 19, 2021
California Environmental Quality Act
The MCOSD prepared a draft Initial Study/Mitigated Negative Declaration (IS/MND) for the proposed Cascade Canyon Bridges and Trail Improvement Project. The IS/MND provides information regarding the setting of the project area, the project description, analysis of potentially significant environmental impacts that could result from implementation of the proposed project, and mitigation measures to reduce potentially significant environmental impacts to a less than significant level. The Notice of Intent to Adopt a Mitigated Negative Declaration and the draft IS/MND can be accessed using the links provided below.
The public comment period ended on March 19, 2021. The MCOSD considered comments received during the public comment period prior to finalizing the IS/MND.
- Notice of Intent to Adopt a Mitigated Negative Declaration
- Draft Initial Study/Mitigated Negative Declaration
- Online Public Meeting Announcement
Improving visitor safety and preserving habitat in Cascade Canyon
2013
Initial neighborhood meeting on site
2015
Region 2 Road and Trail Management Plan designation meeting
2016
• Community meeting at the Fairfax Women’s Club
• Fairfax Town Council open session public meeting
2016–2018
Regulatory agency office presentations and 2 site visits:
• US Army Corps of Engineers, • California Department of Fish and Wildlife • San Francisco Bay Regional Water Quality Control Board
2017
• Neighborhood meeting on site with Supervisor Katie Rice
• Town of Fairfax Memorandum of Understanding signed 5/23/17
2017–2018
Marin County Open Space District Environmental Roundtable monthly meetings
2018
Neighborhood meeting regarding FHYLF and bridges
2018-2020
Presentations at three Parks and Open Space Commission public meetings
2021
• CEQA (California Environmental Quality Act) public review and comment February 16 to March 19. 190 comments submitted.
• Zoom Public meeting with Q/A regarding CEQA on March 4, 2021.
• MCOSD prepares conceptual restoration plan to address comments
2022
MCOSD prepares Traffic Study to address comments
2023
CEQA responses to comments published on October 23, 2023
Marin County Open Space Board of Directors public meeting on October 28, 2023. CEQA certified and project approved.
2026
Construction scheduled to begin on one of two trail bridges.
Improving visitor safety and preserving habitat in Cascade Canyon
Preliminary Trail Report
A preliminary trail report that included the Cascade Trail Bridges project was prepared by Timothy C Best, CEG Engineering Geology and Hydrology in 2013. MCOSD representatives met with neighbors on-site in December 2013. The preliminary trail report was utilized during the Road and Trail Management Plan trail designation process, which included public outreach and public comment. The designation process for Region 2 occurred in late 2015. It included a public workshop held on October 3, 2015 and a Region 2 Designation Meeting on November 30, 2015.
Project Proposal
The Cascade Trail Bridges project originated as a proposal submitted to MCOSD for consideration by Friends of Corte Madera Creek Watershed and the Marin County Bicycle Coalition on April 14, 2016.
A public meeting on the project was held at the Fairfax Women’s Club on September 8, 2016. The purpose of this meeting was to provide the community with information on project planning and hear public comments. Additionally, Daniel Logan a Fishery Biologist from the National Marine Fisheries Service presented information on San Anselmo Creek fish populations and the benefits of reduced erosion and sedimentation expected of the proposed project.
The proposal was evaluated and scored using methodology approved as part of the RTMP. It was then accepted as a proposed project.
A Species of Special Concern
A species of special concern, foothill yellow-legged frogs were once widespread throughout California and Marin County. However, decades of land development, dam building, and harmful agricultural practices drastically decreased their numbers. In Marin County today, these frogs are only found in a few creeks in isolated, disconnected watersheds, including Cascade Canyon. Today, land managers, scientists, and volunteers are working together to protect the frog populations that are struggling to survive in Marin. Learn more about Foothill yellow-legged frogs at One Tam.
Memorandum of Understanding with the Town of Fairfax
In December 2016, the proposed project was presented to the Fairfax Town Council in open session to seek authorization to proceed. Authorization from the Fairfax Town Council was needed because most of the project area is located within the Elliott Nature Preserve portion of the Cascade Canyon Open Space Preserve. The Elliot Nature Preserve was transferred to the MCOSD in 1987 from the Town of Fairfax. However the Town of Fairfax retains approval authority over any improvements within this portion of the Cascade Canyon Open Space Preserve through a deed restriction. At this meeting, the Fairfax Town Council voted to approve a Memorandum of Understanding (MOU) in favor of moving forward with the Cascade Trail Bridges.