The economy of Washington is tightly connected to the vast hydroelectric development of the state. During the Great Depression of the 1930s, the federal government laid the framework for a series of hydroelectric dams harnessing the immense water power of the Columbia River. When the first of these, the Bonneville Dam, came on line in 1938 it helped the Pacific Northwest to diversify its economic base from timber and agriculture to manufacturing. Aluminum was one of the first new industries.
This strong and light weight metal quickly became important during the Second World War, where it was used in aircraft such as the B-17 Flying Fortress and the P-51 Mustang and also in naval vessels such as Liberty ships. The first aluminum rolling plant at Trentwood produced millions of square feet of rolled aluminum during the war. After the war the plant was sold to The Permanente Metals Company, forerunner of the Kaiser Aluminum and Chemical Corporation.
Post-war economic prosperity helped drive the continued expansion of the aluminum industry in the Pacific Northwest, and cemented Kaiser's role in the region as a modernizing force. By 1950 nearly half of national output of aluminum was produced in Washington. The Trentwood plant was remodeled beginning in the 1970s to keep it competitive edge in the emerging global market. Labor disputes in the 1980s caused the shutdown of other local Kaiser plants, but the Trentwood facility remained open. Today the plant is still in operation and a recent major overhaul improved its viability in today's hyper competitive global market.