Driving through the Dalles, the central attraction is the huge dam spanning the Columbia River. Although it was built in 1960, it is a reminder of the massive amounts of hydropower that the Northwest produces, and has produced for generations. Although hydropower had been used for eons, it became popular on a large scale at the beginning of World War II, when the US needed additional electricity to power the factories that were producing the machinery the army needed; new dams were a quick and relatively cheap way to add capacity. Most of the new hydropower was concentrated in the northwest, where the Columbia River could supply the electricity needed to process the abundant natural resources, especially aluminium, found in the area; industrial plants - shipyards, steel mills, chemical companies, oil refineries, and automotive and aircraft factories - soon migrated to the area to take advantage of the profitable combination. (Boeing's plants in Seattle are a legacy of this movement.) Even atomic energy installations were located at Hanford, Washington, to make use of the hydropower.