Butte is the county seat of Silver Bow County, Montana, United States. In 1977, the city and county governments consolidated to form the sole entity of Butte-Silver Bow. The city covers 718 square miles (1,860 km2), and, according to the 2010 census, has a population of 33,503, making it Montana's fifth largest city. It is served by Bert Mooney Airport with airport code BTM.
Established in 1864 as a mining camp in the northern Rocky Mountains on the Continental Divide, Butte experienced rapid development in the late-nineteenth century, and was Montana's first major industrial city. In its heyday between the late-nineteenth and early-twentieth centuries, it was one of the largest copper boomtowns in the American West. Employment opportunities in the mines attracted surges of Asian and European immigrants, particularly the Irish; as of 2017, Butte has the largest population of Irish Americans per capita of any city in the United States.
Butte was also the site of various historical events involving its mining industry and active labor unions and Socialist politics, the most famous of which was the labor riot of 1914. Despite the dominance of the Anaconda Copper Mining Company, Butte was never a company town. Other major events in the city's history include the 1917 Speculator Mine disaster, the largest hard rock mining disaster in world history.
Over the course of its history, Butte's mining and smelting operations generated in excess of $48 billion worth of ore, but also resulted in numerous environmental implications for the city: The upper Clark Fork River, with headwaters at Butte, is the largest Superfund site in the United States, and the city is also home to the Berkeley Pit. In the late-twentieth century, cleanup efforts from the EPA were instated, and the Butte Citizens Technical Environmental Committee was established in 1984.