On October 19, 1915, a devastating dynamite explosion at the Granite Mountain Mine in Butte, Montana, killed sixteen men and injured three others, marking one of the significant industrial tragedies in the city's copper-mining history. The disaster occurred at the surface of the mine, where explosives were being prepared for transportation underground. Located in Silver Bow County and operated by the North Butte Mining Company, Granite Mountain was an important component of Butte's extensive mining industry. The explosion exposed the dangers associated with handling powerful commercial explosives and became an early chapter in the history of a mining property subsequently associated with one of America's deadliest mining catastrophes.
The North Butte Mining Company was incorporated in Minnesota on April 1, 1905, by Charles A. Duncan, Louis W. Powell, and Joseph B. Cotton. Authorized capitalization totaled nine million dollars, although the corporation ultimately issued six million dollars in stock. James Hoatson of Calumet, Michigan, became its first president, while Arthur C. Carson served as general manager. The company acquired the Speculator Mining Company's properties in June 1905, establishing substantial copper-mining operations in Butte. Its initial production exceeded thirty million pounds of copper, valued at approximately five million dollars, demonstrating the commercial importance of the enterprise.
In 1909, North Butte purchased the Granite Mountain Mine from interests associated with the Lewisohn brothers. During the following five years, workers deepened the Granite Mountain shaft from approximately 500 feet to 2,800 feet, matching the depth of the neighboring Speculator shaft. By 1915, Granite Mountain had become the company's primary operating shaft, while Speculator served as an auxiliary hoisting and ventilation facility. These improvements formed part of a substantial expansion of North Butte's mining operations. The company's copper production had reached thirty-three million pounds in 1909, generating dividends totaling approximately $1.6 million.
The October 19 catastrophe occurred during the routine preparation of blasting explosives for underground use. According to the United States Bureau of Mines, thirteen boxes of 40-percent gelatin dynamite detonated near the collar, or surface opening, of the Granite Mountain shaft. The explosives had been loaded into a steel mine car positioned on the gallows-frame turnsheet, approximately twenty feet northwest of the shaft opening. The car was awaiting transportation underground when the dynamite unexpectedly exploded.
The immediate consequences were catastrophic. Fourteen miners died instantly, while two additional workers sustained fatal injuries and died within several hours. Three other men suffered injuries of varying severity. The Bureau of Mines recorded sixteen fatalities, although the Montana Historical Society's archival description of North Butte Mining Company records reports fifteen deaths. The federal disaster compilation provides the more detailed casualty account, distinguishing fourteen immediate fatalities from two subsequent deaths.
The precise cause of the detonation remained undetermined. Federal investigators documented the possibility that a rifle bullet had initiated the explosion, but they did not establish that explanation as fact. The distinction is historically important because the surviving federal account does not identify a confirmed ignition source. What the investigation established was that a substantial quantity of gelatin dynamite exploded while standing in a mine car at the surface, illustrating that significant mining hazards existed outside underground workings.
The disaster also entered the documentary history of the North Butte Mining Company. The Montana Historical Society preserves corporate records that include correspondence between general manager John D. Pope and company attorney D. Gay Stivers concerning the 1915 explosion. The collection additionally contains a scrapbook of newspaper clippings assembled by Al Hooper concerning the Granite Mountain disasters of 1915 and 1917. These materials provide important archival evidence for studying the company's response and the public reporting of its industrial accidents.
The 1915 explosion preceded another deadly incident at the company's Pennsylvania Mine in February 1916 and the catastrophic Granite Mountain–Speculator fire of June 8, 1917. The latter disaster killed more than 160 miners and became the deadliest hard-rock mining disaster in American history. The two Granite Mountain tragedies were separate events, involving different causes and circumstances, but occurred at the same mining property within twenty months.
The historical significance of October 19, 1915, rests in its documented human cost, the handling of industrial explosives, and its place within Butte's mining history. Sixteen workers lost their lives during preparations for ordinary mining operations. Their deaths remain part of the historical record of industrial labor in Montana, illustrating the hazards accompanying the copper production that helped establish Butte as one of the nation's foremost mining centers.
References / More Knowledge:
1. United States Bureau of Mines. Major Disasters at Metal and Nonmetal Mines and Quarries in the United States (Excluding Coal Mines). Federal mining disaster compilation, pp. 15–16. Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health.
https://stacks.cdc.gov/view/cdc/161398/cdc_161398_DS1.pdf
2. Montana Historical Society, Library and Archives. North Butte Mining Company Records, 1905–1934. Collection MC 290. Archival finding aid, Archives West.
https://archiveswest.orbiscascade.org/ark:80444/xv21559
3. Harrington, James D. “A Reexamination of the Granite Mountain–Speculator Fire.” Montana: The Magazine of Western History, Autumn 1998. Montana Historical Society.
https://mhs.mt.gov/education/docs/CirGuides/Harrington-Butte-1998.pdf
4. Butte-Silver Bow Public Archives. Granite Mountain Mine: 1887–1944, 3700 Feet Deep. Story of Butte, historical photograph and archival collection, including documentation of the 1915 explosion.
https://storyofbutte.org/items/show/3388
5. Montana Historical Society. Montana Facts: Speculator Mine Disaster, Butte. Montana Historical Society Research Center.
https://mhs.mt.gov/Research/Compass/Facts