Custer Mine, owned and operated by the Truax Traer Coal Company, was a working surface mine from 1947 to 1964, using strip mining because the lignite coal seam lay near the ground surface. The coal was mined and prepared there, then shipped by rail or sold locally, and the mine employed up to sixty people. In 1950, its most productive year, it produced 370,530 tons of coal. The site also includes the Hummel Mine, an underground coal mine operated in the 1930's, where the coal seam was reached through an inclined shaft and the coal was brought to the surface in small rail cars. During its operating years, Custer Mine had a miniature company town with its own water system, sewer system, central heat, small houses for miners' young families, an elementary school for their children, and a cookhouse that prepared and served meals for the miners. Because before 1975 no laws required mine land to be returned to equal or better productivity, Custer Mine is an example of unreclaimed mine lands, in contrast to modern reclamation methods that can leave surface-mined land difficult to distinguish from untouched land.