sentences:  The switch from underground to open-pit mining stemmed from a series of fires, some burning for decades, in the mine's high-sulfur ores.Removing the overburden and pouring a mixture of water, waste ore, and sand into rock fissures helped control the fires.By 1918, UVX also had its own smelter in its own company town near Cottonwood; the company town was named Clemenceau in 1920.