Built in 1918 for the Washoe Smelter of the Anaconda Copper Mining Company, the Anaconda Smelter Stack is a monumental brick smokestack in Anaconda, Montana, and the tallest surviving masonry structure in the world. It began operating in 1919, drawing furnace exhaust through flues to create a powerful natural draft while also helping recover valuable metal dust from smelter gases. After the Washoe Smelter closed in 1981 and the rest of the complex was demolished, the stack survived through a local “Save the Stack” campaign. It remains the most visible remnant of the region’s copper-smelting era and a powerful landmark of Montana’s industrial history.