Washington Title Image Large
© Pete Saloutos/Panoramic Images (Washington Title Image Large)

Puget Trough Ecoregion

A great inland arm of the sea—Puget Sound—flanked by forested foothills and freshened by many rivers. The Puget Trough ecoregion is home to over 75% of Washington’s citizens.


The Puget Trough ecoregion runs the length of Washington, rising to about 1000 feet elevation between the Cascade Mountains on the east and the Olympic Mountains and Willapa Hills on the west.

Interstate Highway 5 connects most of the Puget Trough’s urban centers: Vancouver, Centralia, Olympia, Tacoma, Seattle, Everett, Mt. Vernon, Bellingham. Rapidly growing communities such as Puyallup, Kent, Renton, Bellevue, and Redmond lie east of I-5.

Encompassing about 8% of Washington State’s area, this ecoregion is densely populated. It is part of the larger Willamette Valley-Puget Trough-Georgia Basin ecoregion that extends south into Oregon and north into British Columbia.


For details of this ecoregion within Washington, click a subheading in the left column.

View the more general description of this ecoregion in North America

Go to the Map

Use the interactive map to zoom smoothly from a national view to state and local perspectives anywhere across the country.

Copyright © 2023 NatureServe. All Rights Reserved.