Stillwater (PGM)


LOCATION: Montana, United States
OPERATOR: Sibanye-Stillwater

The Stillwater complex is comprised of the Stillwater mine and East Boulder mine in Montana and is operated by Sibanye-Stillwater, following the acquisition of Stillwater Mining Company by Sibanye Gold Limited in May 2017. Production began in 1986 at the Stillwater mine and in 2002 at the East Boulder mine. Both are PGM mines with the majority of production being palladium.

Franco-Nevada has a 5% NSR royalty on all commercially recoverable metals produced from 813 of the 995 claims that cover the Stillwater complex. The amount of the royalty is reduced by permissible “onward processing” deductions, which have averaged between 10-12% of revenue over the last several years.

Based on Franco-Nevada’s estimates, the NSR royalty currently covers over 95% of the Stillwater Mineral Reserves and 100% of the East Boulder Mineral Reserves. In recent years, the percentage of Stillwater complex production subject to Franco-Nevada’s royalty has increased above 90% as mining moves away from the shaft area.

PGM production for 2020 yielded 603,067 ounces versus 593,974 ounces in 2019, which included production from the Blitz (Stillwater East) project, as discussed below. A meaningful increase in PGM production from Stillwater is forecast for 2021. PGM production is forecast to be between 660,000 to 680,000 ounces.

The Blitz (Stillwater East) project, located east of the Stillwater mine (Stillwater West) and covered by the NSR, commenced production in October 2017. The Blitz (Stillwater East) project has indicated a delay of up to two years to achieve full production. Stillwater has experienced various operational challenges and disruptions over the last 18 months towards Blitz (Stillwater East). These include unplanned ground conditions, ventilation constraints and higher than expected water ingress. COVID-19 has also caused production challenges which negatively affected productivity and caused equipment and material delays as a result of associated supply chain challenges. When production is at steady state the run rate is expected be approximately 300,000 ounces per annum starting in 2024.

Sibanye-Stillwater estimates that both the Stillwater and the East Boulder mines have mine lives in excess of 25 years based on existing Mineral Reserves. Significant Mineral Resources have the potential to increase mine life even further in the future.


  • Only PGM producer in the U.S.
  • Blitz (Stillwater East) expected to increase PGM production by 50% by 2025
  • Current Mineral Reserves support a long mine life
  • Significant Mineral Resource potential to increase mine life even further

2020 2019 2018
Revenue to Franco-Nevada ($ million) $ 50.9 $ 39.8 $ 21.3