Born-Digital or AnalogAnalogTranscriptEmpire tunnel (Clear Creek County, Colorado) Description of Empire Tunnel and Gold Mining, Milling and Transportation Co.'s operation of the Tunnel. Mi-Co Clear Creek empCollectionWestern History Subject IndexRelated MaterialWestern History Subject Index AbbreviationsType of MaterialIndex CardLanguageeng
Empire tunnel (Clear Creek County, Colorado), [239576]. Denver Public Library Digital Collections, accessed 13/06/2025, https://digital.denverlibrary.org/nodes/view/1484057
