Mullan is a city in the northwest United States, located in the Silver Valley mining district of northern Idaho. The population was 646 at the 2020 census and 692 at the 2010 census, and 840 in 2000. In Shoshone County at the east end of the Silver Valley, Mullan is in a sheltered canyon of the Coeur d'Alene Mountains at an elevation of 3,278 feet above sea level.