Washington's water resources provide both irrigation and enormous hydroelectric power. The impact of the Columbia River on the life and economy of the state can scarcely be overestimated. In early days the river was a means of transport and a salmon-fishing field for many Native American tribes. Because of the steep drop from its origin to its mouth, the Columbia is one of the greatest sources of hydroelectric power in the world. Grand Coulee Dam—one of the world's largest concrete dams and greatest potential power-producing structures—and Bonneville Dam have been supplemented, on the river's upper course, by Chief Joseph and Rocky Reach dams (both completed 1961), Priest Rapids Dam (1962), and Wanapum Dam (1963), and, on its lower course, by The Dalles Dam (1957), John Day Dam (1968), and McNary Dam (1953), all shared with Oregon.
The dams on the Columbia's lower course were designed as power, flood-control, and navigation projects, whereas the dams on the upper course are integral to the Columbia basin project (with the Grand Coulee as the key unit), providing not only power and flood control but extensive irrigation to the Columbia Plateau. The Snake River in the east and the Yakima River in S central Washington also have important irrigation projects. Dams on the Skagit River (including Ross and Diablo, two of the world's highest) supply power to Seattle and the surrounding area.
Puget Sound is the heart of Washington's industrial and commercial development. It is navigable and has many beautiful bays, on which are situated such commercial and industrial cities as Seattle, Tacoma, and Everett. Seattle, an exporter and importer in trade with Asia and a gateway to Alaska (because of the protected Inland Passage), is a major U.S. city and a center for the manufacture of jet aircraft (as well as missiles and spacecraft) by the Boeing Corp. In recent years, computer software (Microsoft Corp. is near Seattle), electronics, and biotechnology have become increasingly important to the economy.
Washington's huge food processing industry is based on the state's diversified irrigated farming and dairying as well as on its abundant fishing resources. Salmon is the biggest catch, but halibut, bottomfish, oysters, and crabs are also significant.
Much of the land in E Washington is used for dry farming. Irrigation, however, has converted many of the river valleys east of the Cascades (especially the Yakima and Wenatchee) into garden areas. This region contains most of Washington's vineyards; from the 1980s the state has developed an important wine industry. Washington leads the country in the production of apples, sweet cherries, and pears and is a major wheat producer, chiefly in the hilly southeastern Palouse area. Washington is also a major producer of corn, onions, potatoes, apricots, grapes (including those made into wine), and other fruits, nuts, and vegetables. Cattle, dairy goods, sheep, and poultry are also economically important. Spokane is the commercial and transportation hub of the entire "Inland Empire" region between the Cascades and the Rockies, which extends into British Columbia, Idaho, Montana, and Oregon.
Despite the vast semiarid expanse E of the Cascades, more than half of the state's area is forested, and the lumber and wood-products industry, so important in the early development of the state, remains one of its largest. Many of Washington's cities (among them Tacoma, Bellingham, Everett, and Anacortes) began as sawmill centers—Seattle itself was home to the original "Skid Road"—and lumber, pulp, paper, and related items are still among their major products.
Other important manufactures in the state are chemicals and primary metals, especially aluminum. Abundant water power and the rich aluminum and magnesium ores found in the Okanogan Highlands in the northeast part of the state have made Washington the nation's leading aluminum producer. Washington's chief minerals are sand and gravel, cement, stone, and diatomite. Gold, lead, and zinc are also found in the Okanogan Highlands. Tourism is an increasingly important industry.