The goal of this restoration project was to restore Lower Quinault floodplain riparian habitat that has been degraded by invasive plant species such as knotweed and reed canary grass. These invasive species cause great damage to salmon habitat by displacing native vegetation that maintains natural ecosystem functions. These plants contribute to soil erosion; impair water quality; create a gap in the aquatic food web; and choke out stream channels that salmon species use for migration and overwintering. This project aimed to improve habitat and support Chinook, chum, coho, and sockeye salmon; bulltrout; and steelhead and cutthroat trout populations native to the Lower Quinault River. This multi-year effort, as prescribed by the WRIA 21 Strategy, was to control invasive species in the Quinault Watershed using a top-down approach. The first year of the project covered 7,883 acres and the upper 6 miles of the Lower Quinault River watershed for a total of 22.68 river miles treated. Plants were treated using EPA-approved aquatic herbicide with low-pressure backpack sprayers. Infestations were documented, tracked, and mapped using GPS units and ArcGIS. During the following years, crews used survey and mapping information from the first year of treatment to spot-check and re-treat identified infestations. The Quinault Indian Nation (QIN) was the sponsor for this project. The QIN has partnered with Grays Harbor County, Olympic National Park and Forest, Rayonier, and private landowners in other knotweed projects in the Quinault watershed.