Front: "Main Office E.Z.;" verso: "Mine office at Gilman, Healy's Grocery to the right" E.Z. noted above was "Empire Zinc Co., formed in 1902 to search for and develop zinc mines in the west. The Eagle mine, operated by the Empire Zinc Division of the New Jersey Zinc Company at Gilman, Colorado, thirty miles west of the Continental Divide, was acquired in 1915." -- The First Hundred Years of the New Jersey Zinc Company, p.29 New Jersey Zinc...