We're about to find out whether wild fish and clean hydropower can coexist. Maine's lower Penobscot River has been plugged with eight dams since 1910. Now, an unparalleled partnership—between environmental organizations; state, federal, and tribal governments; and hydropower interests—is taking down two of the lowermost dams and retrofitting a third with an innovative fish pass that resembles a natural river channel. The project will restore fish access to 1,000 miles of habitat by 2013. And the river will produce the same amount of power: PPL Corporation, owner of multiple dams on the Penobscot, will increase hydroelectric production at six small existing dams. Optimists expect threatened American shad to recover and the Atlantic salmon population to increase from less than 1,000 to 10,000 within a decade. But the most lasting impact of the project might be its value as a viable new model. "It shows that we can remove dams and increase power within the same river basin," says Stephanie Lindloff, senior director of river restoration at American Rivers, an environmental nonprofit.