part of Northern Rocky Mountains, located in northern Idaho along Montana border in Kootenai and Shoshone counties of Idaho and Mineral and Sanders counties of Montana; stretch about 95 mi (153 km) from Lake Pend Oreille to St. Joe River; also bounded by Coeur d'Alene River, St. Regis River, and Coeur d'Alene Lake; highest peaks in eastern section are 6,000 to 7,000 ft (1,800 to 2,100 m) high; part of Bitterroot range; Coeur d'Alene National Forest covers most of range; mines produce most of Idaho's silver, lead, and zinc.