This dataset was updated in January 2013 to make use of newer watershed boundaries that better depict the freshwater range of Pacific salmon and steelhead under NOAA Fisheries' jurisdiction. They are provided for general reference only and do not constitute a legal description of any species listed under the U.S. Endangered Species Act.This evolutionarily significant unit, or ESU, includes all naturally spawned populations of Chinook salmon from rivers and streams flowing into Puget Sound, including the Strait of Juan De Fuca from the Elwha River, eastward, including rivers and streams flowing into Hood Canal, South Sound, North Sound and the Strait of Georgia in Washington, and 26 artificial propagation programs.