ANACONDA, Montana – Bit of dirty ski mission in Anaconda, Montana where Robert Lester climbed to the top of copper smelting slag site and pointed his skis downhill. Closed in 1980, smelting operations in Anaconda are a distant memory, but the black slag hill stands as a relic of southwest Montana’s mining boom and bust. Surreal feature to ski down.
The slag hill is byproduct of over 100 years of copper smelting and is comprised of around 130,000 cubic yards of slag. According to the EPA, slag is mostly copper sulfide, copper-iron sulfide, and copper-arsenic sulfide. Up close, Anaconda slag is black and glassy, granular like sand. While some slag clumps into a solid mass, the water-cooling process used in Anaconda prevented this.
Around 195 acres, or about the size of 147 football fields, are covered in slag in Anaconda. Those piles fill an estimated volume of 16.1 million cubic yards. While the slag itself is relatively stable, the dust within the slag could contain hazardous metals. This only becomes a serious hazard with very high doses, so exposure while playing golf at the Old Works Golf Course, which uses the slag for sand traps, isn’t harmful.