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.
- Counties: Snohomish
- National Estuary Programs: Puget Sound
- Other Watersheds Upstream: Skykomish, Snoqualmie, Puget Sound
- Other Watersheds Downstream: Puget Sound