Encompassing 184,674 sq km (71,303 sq mi), Washington ranks 18th among the states in land area and, with 4,866,692 inhabitants (1990 census), 18th in population. The population is increasing at a greater rate than the national average.
Thousands of years of occupancy by American Indians were interrupted during the late 18th century by the arrival of European and American explorers and traders. The ensuing fur trade gave way to permanent white settlement during the 1840s. Washington, with its capital at OLYMPIA, became a territory in 1853 and in 1889 became the 42d state. Long noted for its abundant natural resources of water, timber, and fish, today Washington is a leader in the aerospace industry, international trade, and tourism.
Land & Resources
Washington is characterized by greatly varying relief and scenery. Although the rough outline of Washington’s coast totals only 253 km (157 mi), the actual coastline is 4,870 km (3,026 mi) because of the many inlets and small islands in PUGET SOUND. The Strait of JUAN DE FUCA and the adjoining Puget Sound and Strait of Georgia separate the Olympic Mountains (highest peak, Mount Olympus, at 2,428 m/7,965 ft) on the Olympic Peninsula from British Columbia’s Vancouver Island. To the east and southeast of the sound is a coastal plain, the Puget Sound lowland. To the east the lowland gives way to the CASCADE RANGE (highest peak, Mount Rainier, at 4,392 m/14,410 ft). Scarred and sculpted by glaciers and ice sheets, the Cascades are dominated by dormant volcanoes, in addition to Mount Rainier (including Adams, Baker, and Glacier). Another volcano in the Cascades, Mount St. Helens–dormant since 1857–erupted in 1980, causing extensive damage mostly from volcanic ash. To the far east lie the lower slopes of the ROCKY MOUNTAINS. In the north are the Okanogan Highlands. Enclosed by the mountains (except in the southeast) lies the roughly triangular-shaped Columbia Basin, which incorporates incised coulees, lava plateaus, and undulating hills. The Columbia Basin and the Puget Sound lowland constitute Washington’s only extensive level areas.
Under the influence of prevailing westerly winds and the rain-shadow effect of the Cascades, Washington is divided into two major climatic regions: a moist, temperate zone to the west with approximately 500 to 3,800 mm (20 to 150 in) of precipitation and an annual temperature fluctuation of 8 to 11 C degrees (14 to 20 F degrees), and a drier, somewhat continental eastern region with 200 to 635 mm (8 to 25 in) of precipitation and a temperature range of 25 deg to 28 deg C (45 deg to 50 deg F). Summer is the dry season throughout almost the entire state, and cyclonic storms from the west constitute the most frequent and regular meteorological disturbances.