Lake Coeur d'Alene in northern Idaho is a glacial lake shaped by the last Ice Age, when the Missoula Floods and Cordilleran Ice Sheet reshaped the region. Fed by the Coeur d'Alene and Saint Joe rivers and draining through the Spokane River, its level is now controlled by Post Falls Dam, which also expanded its shoreline. Long a cultural center for the Schitsu’umsh, or Coeur d'Alene people, the lake later became important to the region's lumber economy and remains partly owned by the Coeur d'Alene Tribe. Today it is a major recreation area, while pollution from historic mining and smelting continues to threaten water quality.