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This page is under review. For the latest information, please refer to our Integrated Annual Report 2018, released on 29 March 2019.


Stillwater mine, including the Blitz section, is located near the town of Nye. East Boulder Mine is located near the town of McLeod. Both are shallow to intermediate level underground PGM mines. PGM production commenced in 1986 and has largely been uninterrupted.

The mining assets are located in the front range of the Beartooth Mountains with elevations exceeding 1,524m above mean sea level (amsl). Several river valleys have eroded into the mountainous terrain with the Stillwater River valley providing reef access to Stillwater. The two mines are within the Custer and Gallatin national forests, approximately 42km to the north of Miller Mountain and Wolverine Peak. The Stillwater River generally flows from the south to the north-east.

Snow in the winter occasionally poses adverse operating conditions. Snow can have an impact on mine site access but avalanches have never been an issue in the steep terrain. Heavy snows, stream flooding or forest fires are the only significant environmental factors affecting site access but these have not significantly hindered operations since mining commenced at Stillwater and East Boulder.

R&F stopes are the predominant mining method (85%) at Stillwater and East Boulder. While the primary method is by overhand mining, some undercut R&F is used. Of the R&F stopes, overhand R&F stopes constitute 90% and underhand R&F stopes account for 10%.

All surface infrastructure and tailings management facilities are located within Stillwater and East Boulder mine operating permits, which covers an area measuring 1,396ha.

Stillwater has two principal mining sections, namely:

  • The current section, which has been in operation since 1986 and currently produces 676ktpa of Pt and Pd in concentrate
  • The Blitz section, which is currently under development, started ore production in 2017

All legal aspects and tenure are in order.

East Boulder has been in operation since 2002 and currently produces 580ktpa of Pt and Pd in concentrate.

In 2017, for the eight months under Sibanye-Stillwater’s control, the US PGM operations sustained their operating performance and reported 2E PGM production of 376,356oz. This compares favourably with mined 2E PGM production of approximately 363,874oz for the same period in 2016 and the 2017 guidance. East Boulder delivered record 2E PGM production of 93,725oz during the eight-month period while Stillwater contributed 282,631oz, which includes production of approximately 7,000oz by the Blitz project which was commissioned three months ahead of schedule.

Locality plan

Operations in Montana - USA


Ore milled000t 855
Plant head grade g/t 15.01
Plant recoveries% 91.00
Yieldg/t 13.69
PGM production (4E – 2E)000oz 376
PGM sales (4E – 2E)000oz 355
Price and costs
Average PGM basket price receivedR/oz 12,330
Adjusted EBITDA margin% 23
All-in sustaining costR/oz 8,707
US$/oz 651
All-in costR/oz 11,097
US$/oz 821
Capital expenditure
Ore reserve developmentRm 539
Sustaining capital Rm 227
Corporate and projectsRm 888
Total Rm 1,654