The Hull-Rust-Mahoning Mine in Hibbing, Minnesota, is the largest open pit iron mine in the world. The mine, located in the Mesabi Range, supplied as much as one-fourth of all the iron ore mined in the United States during its peak production years of World War I and World War II.
This area of the Mesabi Range was explored in 1893–1894, shortly after the Mountain Iron mine was established in 1892. The early development was as an underground mine, but open cast mining soon proved to be a better choice because of the soft, shallow ore deposits. Many open pits in the area soon merged into one large mine, and the consolidation of mines led to the formation of U.S. Steel in 1901. The growth of the mine even resulted in the town of Hibbing being relocated to accommodate expansion. The move started in 1919 and took two years to complete at a cost of $16,000,000. 185 houses and 20 businesses were moved, and some of the larger buildings had to be cut in half for the move. Only a few uninhabited remnants of the original townsite are left near an observational lookout at the edge of the mine.
Over 519 million tons of waste material and 690 million tons of iron ore have been removed from the mine area since ore shipments began in 1895. The mine was listed as a National Historic Landmark, and added to the National Register of Historic Places on November 13, 1966. The mine is still operated today by the Hibbing Taconite Company, and taconite pellets are extracted at the rate of 8.2 million tons annually (not counting waste overburden).