Stillwater Mining Company engages in the development, extraction, processing, smelting, and refining of platinum group metals (PGMs). It operates through Mine Production, PGM Recycling, Canadian Properties, and South American Properties segments. The company primarily explores for palladium, platinum, and associated metals, as well as for nickel, copper, gold, silver, and rhodium ores. It conducts its mining operations at the Stillwater mine located near Nye, Montana; and at the East Boulder mine located in Sweet Grass County, Montana. The company also owns and operates a smelter and base metal refinery located in Columbus, Montana, as well as recycles spent catalyst materials. In addition, it develops and explores the Marathon PGM-copper deposit in Ontario, Canada; and the Altar porphyry copper-gold deposit located in the San Juan province of Argentina. The company was founded in 1992 and is headquartered in Billings, Montana.