Built in 1911, Hercules Mill rose 87 feet above the railroad tracks and fed lead-silver concentrates to rail cars from a hillside north of the Coeur d'Alene River, served by the Northern Pacific rail line entering Wallace. By 1914 it ran 24 hours a day, regularly doubling its capacity. In 1925 the mill was retrofitted with innovative flotation technology that provided differential separation of lead-silver and zinc. By 1929 it employed 65 men with a payroll of more than $10,000 a month. When full operation ended in 1949, Hercules Mill had yielded an estimated three quarters of a million tons of lead-silver concentrates. Along with contributing to regional and federal demand for metals, part-owners Levi and Mary Arkwright Hutton established a trust fund to support a children's home that is still operating in Spokane, Washington. Other investors included Eugene, Harry, Jerome, and Henry Day, Emma Markwell, the Ed Hedin family, August Paulsen, Myrtle White, and H.F. Samuels. By 1976 the mill structures had been burned or removed, leaving concrete foundations on the hillside, and in 2012 railroad companies removed facing foundations and conducted soil cleanup while keeping several foundations and concrete structures. The main railroad route near the site is now a 72-mile recreation trailway.