The Granite Mountain–Speculator Disaster of 1917
On the night of June 8, 1917, Butte was a city working at full speed for a nation at war. The United States had entered the First World War that spring, and copper was urgently needed for shell casings, wire, and munitions. The mines on the Butte hill were running around the clock, and about 410 men were underground on the night shift in the Granite Mountain and Speculator mines, two connected workings operated by the North Butte Mining Company on the northern edge of the city.