Railroads and mining in Bingham Canyon have gone hand in hand since the first railroad was constructed in the canyon in late 1873. Bingham Canyon in the early years was a gold and silver mining camp, and the railroads were small operations. Copper mining took hold in the late 1890s, and the mines, mining companies, and railroads that served them expanded rapidly. Bingham Canyon soon became the largest and richest mining district in the western United States and was the source for as much as a third of the copper mined in the nation. A variety of locomotives worked in the canyon, including a small number of Shay locomotives, several large articulated steam locomotives, and the nation's largest roster of electric locomotives. The last Bingham Canyon ore train ran in late 2001. While the railroad tracks have been removed, the mine itself is very much in full production and remains the source for 25 percent of the nation's copper production.