ALPINE TUNNEL, COLORADO SOUTHERN RAILROAD. The highest railroad point in America. Altitude, ft. from the Article THE EVOLUTION OF MINING AND ORE TREATMENT IN COLORADO. By Thomas Tonge. from The Engineering Magazine Devoted to Industrial Progress Volume XVIII 1899-1900 The Engineering Magazine Co

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Size: 3720px × 2247px
Location: Colorado, USA
Photo credit: © Historic Illustrations / Alamy / Afripics
License: Licensed
Model Released: No

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