Born-Digital or AnalogAnalogTranscriptEmpire tunnel and gold mining, milling and transportation company (Clear Creek County, Colorado) Description of its operation of the Empire Tunnel, Mi-Co Clear Creek empCollectionWestern History Subject IndexRelated MaterialWestern History Subject Index AbbreviationsType of MaterialIndex CardLanguageeng
Empire tunnel and gold mining, milling and transportation company (Clear Creek County, Colorado), [238248]. Denver Public Library Digital Collections, accessed 13/07/2025, https://digital.denverlibrary.org/nodes/view/1481230
