31/03/2025
Roy’s Redwoods, a Marin County Open Space property, re-opened to the public this past fall after the implementation of a restoration project through the redwood valley sponsored by Marin County Parks and Open Space District and the Golden Gate National Parks Conservancy. PCI and Restoration Design Group supported the effort with designs for the restoration effort and trail design, constructed by Hanford Arc. The project was funded by multiple sources including the California State Parks Grant, Wildlife Conservation Board Grant, Marin County Accessibility Program, Marin County Measure A funds, and One Tam philanthropic donations.
The park is a favorite for Marin County locals and visitors for its stand of old-growth redwoods tucked away along the valley floor of upper Larsen Creek. This park’s popularity created some ecological challenges stemming from the frequent and long-term use of an expansive network of unofficial social trails. The project goals were to restore natural hydrologic conditions to help ensure that the redwood grove will be resilient and capable of supporting visitor use during periods of extreme drought or excessive rainfall. The restoration activities included decommissioning social trails, relocating segments of existing trails to remove them from sensitive areas, upgrading existing trails to improve drainage and reduce erosion and sedimentation, and other habitat restoration activities.
Social trails in redwood forests can have a significant negative impact on the environment. Redwood forests often have soft, loamy soil characterized by dense leaf cover that plays an essential role in soil composition, the native ecosystem, and hydrology of the forest floor. Social trails kill native vegetation and cause soil compaction that disturb natural conditions, which leads to increased erosion and the formation of gullies. Additional impacts include decreased soil moisture, disrupting wildlife, fragmentation of habitat, and spread of invasive species. These issues cause a positive feedback loop, or sn*******ng effect, that can significantly degrade natural ecosystems.
PCI worked with the design team to develop a restoration design that prioritized improving hydrologic conditions and protecting sensitive habitats, but maintained some of the “explorative/wandering/adventurous” feeling that social trails offer. The design features an “Exploration Area” that allows visitors to stray from constructed paths and puncheons, featuring fallen logs and stumps that lead to a redwood fairy ring with opportunities to wander, build forts, and traverse alternative paths. Beyond this exploration area, the project includes ADA accessible trails and boardwalks that allow for access inside the redwood forest with opportunities to view wetlands, channels, and massive old growth trees. The design is focused around a shallow channel with areas that disperse across the forest floor before joining back together downstream. Carefully placed log structures, rocked grade control structures, and graded areas imitate naturally occurring conditions and create plenty of opportunities for water to disperse and settle without damaging hiking trails, even during high flows. The PCI designers worked together with the trail designers to create an environment that supports high quality ecological function while allowing visitors to enjoy a truly magical space.
The PCI planning and science team prepared a California Environmental Quality Act (CEQA) Initial Study and Mitigated Negative Declaration. PCI planners also applied for and negotiated the necessary permits with state, federal, and local agencies on behalf of Marin County.
Photo labels:
1. Old growth redwood trees
2. Accessible trail through the redwood grove
3. Unofficial trail/road through the meadow
4. Erosion in the meadow
5. Meadow after restoration
6. Constructed trail and log structures
7. Constructed trail and log structures after a rain event
8. Erosion and accumulation of debris before restoration
9. Trail to exploration area
10. Exploration Area
11. Video of restored areas during a rain event