Gold was discovered near Sierra City in the early 1850s, and the Kentucky Consolidated Mining Company formed in 1853. An early stamp mill built in the 1860s had five stamps and was expanded to ten in 1888.
Emil Loeffler began working the mine again in 1920 and started a new mill in 1928 that took five years to build. The mine and mill ran until 1944, and the family worked them off and on until 1953.
Sierra County bought the site in 1974 and restored it. Today it is a historic park and museum, with a three-story mill and a museum in a replica of the 19th-century Bigelow House hotel. Guided tours run the stamp mill, and the drop of the stamps is loud.