Dry plate glass negative depicting two separate exposures taken at the site of the construction of the East Portal of the Moffat Tunnel in Gilpin County during the winter of circa 1922-1923. The left-hand image depicts Frederick Douglas Hall (1866-1938), an African-American man who lived in Denver, Colorado and was employed as an engineer and brake man for the Denver and Rio Grande Western Railroad Company. He stands in front of some of the buildings located at the site and holds a pocket watch. The right-hand image depicts three unidentified men who were likely employed to work on construction of the East Portal. The photo was taken by one of Frederick Hall's sons: Herman Frederick Hall (1893-1984),,Herbert Harold Hall (1893-1961) or Edmeaux Homer Hall (b. 1897). The Hall family was a mixed-race family of African-American descent who lived at 2350 Glenarm Place in Denver.