Hood Canal Salmon Enhancement Group used this funding to for the Highway 101 Causeway Study. The purpose of the study was to 1) define key elements of the study area and existing construction, 2) define improvements and environmental outcomes, 3) characterize the watersheds, and 4) utilize historical data in the establishment of alternative solutions necessary to address significant impacts caused by the existing structures. The goal of this study was to provide information necessary to guide researchers, educators, managers, and decision-makers in evaluating existing efforts intended to protect and restore the Hood Canal’s biological resources, avoid geologic hazards, and explore resource management issues requiring attention now and into the future. Hood Canal is characterized by a series of estuaries that provide an ecological link between freshwater and saltwater habitats. These estuaries support chemical, physical, and biological processes that interact in complex ways to support various life stages of many organisms including Pacific Salmon. Structures associated with the Highway 101 causeway have altered this link between freshwater and marine ecosystems. Therefore, it was critical to identify mechanisms capable of restoring and maintaining processes associated with these naturally functioning estuaries based on scientific research that has broadened our understanding of construction impacts to unique estuarine processes and relationships between these processes and salmon survival.