Calumet Historic District - Calumet, Michigan. Houghton County. National Register, listed March 29, 1989 - http://www.michigan.gov/hal/0,1607,7-160-17449_18638_20846-54480--,00.html
The Heart of the Copper Country, 1880 - A series of photographs depicting the copper industry of Calumet, as it was in 1880. From the American Memory collection of the Library of Congress. - http://hdl.loc.gov/loc.pnp/det.4a07002