The Salmon Habitat Enhancement and Bridge Replacement Project (Project) at Muir Woods National Monument would enhance salmonid habitat in Redwood Creek by placing instream large woody debris and removing existing rock armoring (riprap) along the banks to restore natural channel processes. The Project would also upgrade and replace four aging pedestrian bridges that span the creek. The project is led by the Golden Gate National Parks Conservancy, in conjunction with National Park Service, Golden Gate National Recreation Area, and California Department of Parks and Recreation.

Horizon prepared an Environmental Assessment/Finding of No Significant Impact (EA/FONSI) for NEPA compliance, and conducted technical studies and reports to help assess sensitive resources, such as a wetland delineation, riprap condition assessment, and archaeological surveys. Key issues addressed during the Project planning and development phase inlcuded evaluating potential short- and long-term effects to sensitive resources and the visitor experience, including impacts on aquatic, riparian, and old-growth redwood forest habitats; groundwater resources; special-status plant and wildlife species, such as coho salmon, steelhead, northern spotted owl, and marbled murrelet; Native American resources; and historic park structures constructed during the Civilian Conservation Corps era.