2 core states · Idaho sometimes · 11,942,537 people (WA + OR) · Pacific time
Pacific Northwest states map
The Pacific Northwest is Washington and Oregon, and by many definitions Idaho. Its northern neighbour, British Columbia, belongs to the same region in the geographical sense but is in Canada.
How the region is defined
The Pacific Northwest has a firm core and a soft edge. Washington and Oregon are always included; they share the Columbia River, the Cascade Range and a coast on the Pacific. Idaho is included by most federal and business definitions (the Census, which has no such region, puts it in the Mountain division), and Idaho's own panhandle is on Pacific time and looks to Spokane. Western Montana, southern British Columbia and southeast Alaska appear in ecological definitions built on the Cascadia bioregion, and the term "Cascadia" is used for the same area.
Washington and Oregon had 11,942,537 people in 2020 on 169,677 square miles; with Idaho the totals are 13,781,643 and 253,246. Seattle (737,015) and Portland (652,503) are the two big cities, 175 miles apart on Interstate 5, and Boise (235,684) is the largest inland city.
States, capitals and largest cities
| State | Capital | Largest city | Population (2020) | Area (sq mi) | Included |
|---|---|---|---|---|---|
| Washington (WA) | Olympia | Seattle | 7,705,281 | 71,298 | Always |
| Oregon (OR) | Salem | Portland | 4,237,256 | 98,379 | Always |
| Idaho (ID) | Boise | Boise | 1,839,106 | 83,569 | Sometimes |
| Total, all listed (3 states) | 13,781,643 | 253,246 |
Geography
The region divides sharply at the Cascade Range. West of the Cascades it is wet, green and populated: the Olympic Peninsula and Coast Range, Puget Sound with Seattle and Tacoma, and the Willamette Valley with Portland, Salem and Eugene. The Olympic rainforest receives over 140 inches of rain a year. East of the Cascades it is dry: the Columbia Plateau of central Washington, the high desert of eastern Oregon, and the Snake River Plain of southern Idaho, with 8–15 inches of rain.
The Cascades are a line of volcanoes: Mount Rainier (14,411 ft, Washington's high point), Mount St. Helens (erupted 1980), Mount Adams, Mount Hood (11,249 ft, Oregon's high point) and Crater Lake, which fills the caldera of a mountain that collapsed 7,700 years ago and is the deepest lake in the country at 1,949 ft. Idaho's high point, Borah Peak (12,662 ft), is in the Lost River Range of the Rockies, which cover the state's central and northern parts. Hells Canyon on the Idaho–Oregon border is the deepest river gorge in North America.
The Columbia River ties the region together: it enters Washington from British Columbia, takes the Snake (which drains nearly all of Idaho) near Pasco, forms 300 miles of the Washington–Oregon border and reaches the Pacific at Astoria. Grand Coulee, Bonneville and the other dams on it produce more hydroelectricity than any other US river system. Washington and Oregon are on Pacific time; Idaho is split, with the panhandle Pacific and the rest Mountain.
Related maps
- Official version: Pacific division (WA, OR, CA, AK, HI) and the West region.
- Overlapping informal region: Rocky Mountain states (Idaho).
- Quiz: Western states quiz.
- Cities: Seattle, Portland, Boise; capitals Olympia, Salem, Boise.
- Geography: Cascade Range, Columbia River, Snake River.