Flag of Washington
Largest City Seattle
Capital Olympia
Population 6,830,000
Area 184,827 km²
Highest Point Tahoma   4,394 m

Washington is an American state, and the most populous state/provincial level political entity in Cascadia, and also contains the center of population and most populous city. It is also the only state or province contained completely within the Cascadian bioregion. It covers the southern Salish Sea watersheds, the northern parts of the lower Columbia, most of the middle Columbia, and the lower Snake watersheds, and coastal Cascadia from the mouth of the Columbia River to the Strait of Juan de Fuca.

SE Washington/Palouse (lower Snake)[]

  • Pullman
  • Colfax
  • Walla Walla

Inland Empire (middle Columbia)[]

  • Spokane

NE Washington (middle Columbia)[]

  • Grand Coulee Dam
  • Lower Okanagan
  • Selkirks

Columbia Plateau (middle Columbia)[]

  • Moses Lake
  • Ephrata
  • Columbia Basin Project

Middle Columbia Valley[]

  • The Gorge
  • Wenatchee
  • Chelan

Yakima Valley (middle/lower Columbia)[]

  • Ellensburg
  • Yakima
  • Tri-Cities

SW Washington (lower Columbia)[]

  • Lower Columbia
  • Vancouver
  • Longview/Kelso

Puget Sound/Salish Sea[]

  • Tacoma
  • Bremerton
  • Olympia
  • Seattle
  • Everett
  • Bellingham
  • San Juans


  • Long Beach Peninsula
  • Grays Harbour
  • Olympic Coast
  • Port Angeles

Notable Mountains[]

  • Loowit (Mt St Helens)
  • Pahto (Mt Adams)
  • Tahoma (Mt Rainier)
  • Glacier Peak
  • Mt Baker
  • The Olympics
  • North Cascades