Osceola Mine

[2] In 1873, the Osceola Mining Company formed working the Calumet Conglomerate.

The mine was reopened in the 1950s and permanently closed in 1968 due to the labor strike that shuttered Calumet and Hecla.

[2] The cause is unknown,[2] but the large quantity of timber in the mine contributed to the fire's ferocity.

[2] Thirty people died, including four boys, mostly from smoke inhalation.

[2][4] This makes it the deadliest mine accident to occur in the Copper Country.