Sibanye-Stillwater is an independent, global precious metals mining group and the only US miner of platinum group metals (PGM). The company is based in South Africa with US headquarters in Columbus, MT. Sibanye-Stillwater's Montana operations engaged in development, extraction, and processing of PGMs from a geological formation in south-central Montana known as the J-M Reef, which is the only known significant source of PGMs in the US and the highest-grade PGM deposit known in the world. Sibanye-Stillwater is also the largest global recycler of PGMs derived from spent catalytic converters. The majority of the company's PGMs are used in catalytic converters to reduce vehicle air emissions.