Snohomish Watershed

Location of the Snohomish Watershed in Washington State.  Map courtesy of the EPA.The Snohomish River watershed covers 1,856 square miles in Snohomish and King counties. The Snohomish river travels from the Cascade mountains to Possession Sound, just north of Everett. There are more than 1,700 rivers and tributaries in the watershed, the largest of which are the Snohomish, Skykomish, and Snoqualmie. Where the Snohomish meets the Sound, a saltwater estuary hosts 350 species of birds and hundreds of plants, mammals, and fish.

Nine salmonid species use the rivers for spawning, including Chinook, sockeye, coho, chum, and pink salmon, cutthroat trout, bull trout, and steelhead and rainbow trout. The Skykomish and Snohomish populations of Chinook are both listed as threatened, as well as four bull trout populations. The Snohomish basin produces 25 to 50 percent of Puget Sound’s coho.

EPA watershed profile:

Related WRIA: 07

All Puget Sound WRIAs


Shared Strategy for Puget Sound

Department of Ecology




Snohomish Basin Protection Plan

A 2015 report from Snohomish County, King County and the Tulalip Tribes outlines protection strategies for salmon and salmon habitat within the Snohomish Basin. 

Report cover photo by Victor Mesny.

Climate change vulnerability and adaptation in the North Cascades Region, Washington

A 2014 report by the North Cascadia Adaptation Partnership identifies climate change issues relevant to resource management in the North Cascades, and recommends solutions that will facilitate the transition of the diverse ecosystems of this region into a warmer climate.