Thirty-nine corrugated metal structures mark the site of the Smith Mine, a ghostly reminder of a once vibrant mining district. The Montana Coal and Iron Company (MCI) began developing the Smith Mine in earnest after the arrival of the Montana, Wyoming and Southern Railroad, producing 8,000 tons of high-grade coal in 1907. MCI electrified its operation by 1915, completely mechanizing it by 1929. Throughout the 1930s, the company continued to invest in new equipment, building a new crushing plant, elevator, cleaning plant, coal sheds and scales, electrical substation, and other above-ground structures to support the underground operation. By 1943, miners working three shifts a day, six days a week produced almost 500,000 tons of coal annually, “to meet coal needs for a nation at war.” Investments in safety lagged behind other improvements, however, and in the 1940s many Smith miners still used open-flame carbide headlamps (as opposed to safer electric lamps). The highly gaseous mine also lacked good ventilation or rock-dusting equipment to control coal dust. On February 27, 1943, this proved a deadly combination, when a methane gas explosion in Smith Mine #3 killed seventy-four miners (and later, one rescuer) in the worst coal mining disaster in Montana history. Only three of the men working that day survived. Although MCI closed the Number 3 adit after the explosion, it continued to work its other mines, raking in record profits through 1945. Declining demand, lower quality coal, competition from diesel and natural gas, and bad management led to the operation’s closure in 1953.