What put Crimora on the map was the open-pit Crimora Manganese Mine that started in 1866. The mineral manganese was used in the production of steel. Mining at Crimora continued intermittently under a series of owners until March 1946. The Crimora deposit is about 500 feet wide, 200 feet deep, and half a mile long and consists of clay with scattered lumps of manganese ore. It lies under a layer of clay and quartz fragments about 15 feet thick. The Crimora deposit produced more manganese than any other single deposit in the United States and, at one time, the mining operations there were among the largest in the world.