The Kootenai River, or Kootenay in Canada, flows through southeastern British Columbia, northwestern Montana, and northern Idaho. It begins in the Canadian Rockies; it travels 485 miles before reentering Canada and joining the Columbia River at Castlegar. In Montana, the river courses through Lincoln County, impounded by the Libby Dam to form Lake Koocanusa. This area is excellent for birdwatching, especially during the fall Kokanee salmon run, attracting many bald eagles. Today, the Kootenai River faces environmental challenges from runoff from coal mining operations in British Columbia.