Mining History

In 1889, the Union Concentrator opened in Empire Canyon, setting new levels of efficiency in the concentrating of low-grade ores. The mill could treat more than 100 tons of ore in 24 hours using a crew of only four men and a boy per shift. The Park Record called the mill a "model of completeness, and more nearly what a concentrator should be than any other similar plant in the country." Remnants of the Union are still visible just uphill from the Ridge Avenue turnoff on Daly Avenue.