The Mountains to Sound Greenway Trust completed Conceptual and Preliminary design of an instream restoration project to install large woody material and complete other habitat improvements along the 6,600-foot stretch of Issaquah Creek within Lake Sammamish State Park. In-stream restoration through this reach of Issaquah Creek is scheduled to begin in 2022 (SRFB project 20-1060) and will provide significant habitat benefits for ESA-listed Chinook and other salmonids by providing in-stream structural diversity and more functional and complex habitat, along with continued improvements to the riparian forest buffer through reestablishment of the mixed deciduous-coniferous native tree canopy. This project builds upon nearly two decades of collaborative efforts by the Greenway Trust, Washington State Parks and Recreation, and other partners on restoration along Issaquah Creek within Lake Sammamish State Park and the lower Issaquah Basin. Partners include: the City of Issaquah (numerous completed and active restoration efforts adjacent and upstream on the Creek), King County, Lake Washington/Cedar/Sammamish Watershed (WRIA 8), Kokanee Work Group, the Friends of Lake Sammamish State Park, private businesses and foundations, and thousands of community volunteers. Within the project area, Issaquah Creek is heavily incised in many locations and thus disconnected from the surrounding floodplain, with very little large woody material, resulting in low habitat variability and complexity. This condition adversely impacts habitat for Chinook and other salmonid fish by confining moderate to high flows to a primary, single-thread channel with little high-flow refugia provided and little floodplain activation. To compound matters, there are no longer substantial sources for wood recruitment to provide structure, diversity, and habitat within the channel. The Preliminary Design Report & Appendices (estimated to be between 30% and 60% design) include a detailed assessment of the site, the challenges, the opportunities, and the recommendations for balancing comprehensive restoration within the site, and the conditions for success. Also included in the report is an overview of interest group engagement, and a brief history of work in the area. This project created a comprehensive plan to address these factors along the lower portion of Issaquah Creek, with an emphasis placed on improving juvenile Chinook rearing habitat, emphasizing the restoration of natural processes to permanently restore productive salmonid fish habitat for Chinook and other species. This project identifies a number of improvements that will interconnect to create significant improvements to habitat quality within this stretch of Creek, a relatively unique opportunity for such a large area within an otherwise urban portion of King County.