Stillwater Mining Company is engaged in the development, extraction, processing, refining and marketing of palladium, platinum and associated metals (platinum group metals or PGMs) from a geological formation in the Stillwater igneous complex in south central Montana known as the J-M Reef and from the recycling of spent catalytic converters.

The J-M Reef is a narrow but extensive mineralized zone containing PGMs, which has been traced over a strike length of approximately 28 miles (45 km).

The company operates a smelter and base metal refinery at Columbus, Montana at which it further purifies the mined production to a PGM-rich filter cake.

[2] The South African mining company Sibanye Gold Limited proposed in December 2016 to acquire Stillwater for $2.2 billion ($18/share, a 61-percent premium over its average share price during the previous 52 weeks).

The new owners pledged to honor Stillwater's Good Neighbor Agreement, which requires notification of surrounding communities about anything which might affect them.