The life cycle of native fish in the Pacific Northwest can be a struggle that is impeded at many points, especially when fish passage is compromised by problematic culverts or other barriers. The WA State Initiative for fish passage has spurred the effort to assess culverts state-wide, and NSD is involved in many projects that will improve access to spawning habitat and remove existing fish barriers and infrastructure that impedes the migration of fish. NSD has led multiple fish passage improvement project that replace or remove perched culverts, steep culverts, and other migration barriers. These projects typically include culvert or bridge sizing, sediment transport analysis and streambed aggregate sizing, pool and riffle sequencing, bank stabilization, scour protection, and large wood habitat enhancement.