Now, with the focus in Washington on clean power, some dam agencies are starting to go green, embracing wind power and energy conservation. The most aggressive is the Bonneville Power Administration, whose power lines carry much of the electricity in the Pacific Northwest. The agency also provides a third of the region's power supply, drawn mostly from generators inside big dams.

The amount of wind power on the Bonneville transmission system quadrupled in the last three years and is expected to double again in another two. The turbines are making an electricity system with low carbon emissions even greener -- already, in Seattle, more than 90 percent of the power comes from renewable sources...

Environmental groups contend that the Bonneville Power Administration's shift to wind turbines buttresses their case for tearing down dams in the agency's territory, particularly four along the lower Snake River in Washington State that helped decimate one of North America's great runs of wild salmon.

Bonneville wants to keep all the dams, arguing that they not only provide cheap power but they also make an ideal complement to large-scale installation of wind power. When the wind slows and power production drops, the agency argues, it can compensate quickly by telling the Army Corps of Engineers and the Bureau of Reclamation, which operate the dams, to release more water from reservoirs to turn the huge generators. When the wind picks up, dam operations can be slowed.

The dams help alleviate a need for natural-gas-fired power plants, which are used in other regions as a backup power source when the wind stops blowing, but which release carbon dioxide that contributes to global warming.

John Hildebrand, an animated 82-year-old wheat farmer, has allowed a Spanish developer, Iberdrola, to put wind turbines on his land in Wasco, not far from the Columbia River. Power from his turbines feeds into the Bonneville system.

He and his brother Gordon sat in the front row when Franklin D. Roosevelt dedicated the Bonneville Dam in 1937, before the region even had public power -- so they have seen the future of energy, twice.

"All we had is sky out there," John Hildebrand said, looking out toward the tall structures twirling high above his rolling land. "Now I've got turbines."