Calumet was an industrial center built on the site of an astonishing mineral deposit. The city site is underlain by the empty stopes of the great Calumet and Hecla Conglomerate. Calumet township had a population of about 25,000 in 1900 and 798 in 2010. Remains of the city have been a centerpiece of the Keweenaw National Historic Park. The area has a very strong geoheritage, and this website identifies points of geologic interest (Geosites) within the Township.