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            This is a file from the  Wikimedia Commons. Information from its  description page there is shown below.  Commons is a freely licensed media file repository.  You can help. 
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           | Description | 
           
             English: Composited digital illustration depicting the West portal of the CPRR's "Summit Tunnel" (Tunnel #6) which was in continuous use by the  CPRR,  SPRR, and  UPRR from 1868 to 1993 at  Donner Pass (Norden, California) on Track #1 of the original "Sierra Grade" of the Central Pacific Railroad. (The tracks removed in 1993 have been digitally restored in this illustration.) 
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           | Date | 
           August, 2003  (7 June 2009 (original upload date)) | 
          
          
           | Source | 
           Transferred from  en.wikipedia; transferred to Commons by  User:Sreejithk2000 using  CommonsHelper.  (Original text : The Cooper Collection of US Railroad History (private collection)) | 
          
          
           | Author | 
           DigitalImageServices.com. Original uploader was  Centpacrr at  en.wikipedia | 
          
          
           Permission ( Reusing this file) | 
           
             CC-BY-SA-3.0; Released under the  GNU Free Documentation License. 
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            Centpacrr at  en.wikipedia, the copyright holder of this work, hereby publishes it under the following licenses:
           
           
            
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             Permission is granted to copy, distribute and/or modify this document under the terms of the  GNU Free Documentation License, Version 1.2 or any later version published by the  Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled  GNU Free Documentation License.  http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue 
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