Historically, bull trout had an extensive range in the Elwha River. The dams, which have blocked 70 miles of habitat, greatly reduced the population. Coastal/Puget Sound populations of bull trout were listed as threatened by the Endangered Species Act in November of 1999. Bull trout still exist both above and below the dam, though the anadromous form is considered depressed in the Elwha because of the limited five miles of habitat available for returning anadromous bull trout. Dam removal has the potential of restoring bull trout populations.
—The red line represents the historical range of bull trout. A small number still live in this range, above, between and below the dams.