Every year , those dams kill as many as 90 percent of juvenile salmon and steelhead trout that migrate downstream to the ocean . Report : Rivers in Alaska , California and Georgia are among the 10 most endangered . Comment: Waterways from past American Rivers ' endangered lists have been preserved .
Report : Rivers in Alaska , California and Georgia are among the 10 most endangered . Comment: Waterways from past American Rivers ' endangered lists have been preserved .