The General Office Building is a ​3 ¹⁄₂-story office building built of reddish-brown stone trimmed with brick.
 It was used as a general mine operation center, and also housed engineering and accounting departments.
 The original building was designed in the early 1890s by the Boston firm of Shaw and Hunnewell; two later additions, architecturally faithful to the original, were designed by the Marquette firm of Charlton and Kuenzli.
 Of these three sections, the eastern section measures 69 feet (21 m) by 46 feet (14 m), the western section 22 feet (6.7 m) by 30 feet (9.1 m), and the northern section 46 feet (14 m) by 35 feet.

The building currently serves as the headquarters for the Keweenaw National Historical Park.
The General Office Building is a ​3 ¹⁄₂-story office building built of reddish-brown stone trimmed with brick.  It was used as a general mine operation center, and also housed engineering and accounting departments.  The original building was designed in the early 1890s by the Boston firm of Shaw and Hunnewell; two later additions, architecturally faithful to the original, were designed by the Marquette firm of Charlton and Kuenzli.  Of these three sections, the eastern section measures 69 feet (21 m) by 46 feet (14 m), the western section 22 feet (6.7 m) by 30 feet (9.1 m), and the northern section 46 feet (14 m) by 35 feet.
The building currently serves as the headquarters for the Keweenaw National Historical Park.
Calumet and Hecla Industrial District