Snohomish County

Location of Snohomish County in Washington StateSnohomish County is located on Puget Sound in Washington State.  It is bordered on the west by Island County, the north by Skagit County, the east by Chelan County and the south by King County.  As of the 2010 U.S. Census, Snohomish County had a total land area of 2,087.27 and a population of 713,335.  Everett is the largest city with a population of 103,019.   Also of interest:

  • Intersecting watershed sub-basins(10):  Lake Chelan, Sauk, Lower Skagit, Stillaguamish, Puget Sound, Wenatchee, Skykomish, Snoqualmie, Snohomish and Lake Washington.
  • Major lakes:  Lake Goodwin, Lake Stevens and Spada Lake.
  • Major rivers:  Sauk River, Skykomish River, Snohomish River, Pilchuck River, Stillaguamish River and Snoqualmie River.
  • Glacier Peak (10,541 feet) is part of the Cascade Range and the highest point in Snohomish County.  It is also one of five major composit volcanoes (sometimes called stratovolcanoes) located in Washington State.

U.S. Census Bureau QuickFacts for Snohomish County, WA

Office of Financial Management (OFM) county data for Snohomish County, WA


Tidal forest as viewed from an inner waterway of Otter Island in the Snohomish River estuary. Photo: Jeff Rice/PSI

Tidal forests offer hope for salmon

Can scientists bring back the lost tidal forests of Puget Sound? It could take generations, but restoring this rare habitat will pay big dividends for Puget Sound’s salmon.   


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.

Tidal turbines like this one developed by OpenHydro, Ltd. will be installed in Puget Sound in mid 2015 as part of a demonstration project. Sustainable, large-scale development of tidal energy will require studying and learning from these early-stage projects. Image source: OpenHydro, Ltd./DCNS

Tidal energy in Puget Sound

Scientists have identified the strong underwater currents of Puget Sound's Admiralty Inlet as a potential source of electricity for nearby utilities. The following article describes some of the basic principles and mechanisms of tidal energy.  

Ribbon seal sighted on January 11th, 2012 a dock on the Duwamish River, Seattle, Washington (credit Matt Cleland)

Ribbon seals in the Salish Sea?

Can Puget Sound claim a new species? Ribbon seals were not previously thought to venture into the Salish Sea, but a series of sightings in Puget Sound in 2012 expands their potential range. Scientists are keeping an eye out for future sightings. 


2010 Census Quick Facts for Snohomish County, WA

Learn more about demographics in Snohomish County, Washington.  The U.S. Census Bureau published the following quick facts.

Seaglider in the open water. Photo courtesy of Seaglider Fabrication Center

Seagliders in Puget Sound

They are sometimes called Autonomous Underwater Vehicles (AUVs), or submersible drones. They glide like airships through the deeper channels of Puget Sound, and have become an important tool for a wide array of open ocean applications, including detection of marine mammals, military reconnaissance and the monitoring of environmental disasters like the Deepwater Horizon oil spill. Puget Sound is the birthplace and key testing area of the Seaglider.