Interactive Docs

Butte’s Berkeley Pit

New Life Emerges from its Toxic Waters

Walking up to the Berkeley Pit viewing stand in Butte, Montana is like experiencing a strange, sterile birth. You enter a long, white tunnel lit with fluorescent tubes. A woman’s voice laid over innocuous country music echoes against the smooth walls. The recorded voice describes the history of this bizarre vestige of rabid industrialization: “The richest hill on earth” produced enough copper to pave a four-lane highway four inches thick from Butte to Salt Lake City and 30 miles beyond!” You emerge onto a platform that overlooks the landscape of what appears to be an alien planet– sun-bleached and inhospitable. Highly acidic groundwater contaminated with heavy metals fills the massive expanse. There is no vegetation to be seen. Though it is the city’s most well-known tourist attraction and one of the nation’s largest Superfund sites, what makes it interesting is what you can’t see— the mysterious, otherworldly life that has emerged in its waters due to an unlikely incident with a flock of geese.

The Geese

Watch the video above to learn about the fascinating life growing in the waters of the Berkeley Pit.

On a cloudy November day in 1995, the Pit became the unintended last stop for a flock of snow geese on their migration route. The birds landed on the water, and the foul weather prevented them from leaving for several days. The water proved lethal, and 342 goose corpses were found washed up on the Pit’s embankment.

Pit managers Montana Resources and British Petroleum-Atlantic Richfield Company (BP-ARCO) attributed the fatalities to a pre-existing infection in the geese. These findings were disputed by the State of Montana on the basis of its own lab tests. Necropsies showed the birds’ insides were lined with festering sores from exposure to high concentrations of copper, cadmium, and arsenic.

“It was kind of like the perfect storm,” said Mark Thompson, environmental engineer at Montana Resources in Butte, who started a bird mitigation program to prevent further incidents. “I’m sure, given enough time, it could happen again and that’s why we continue to haze [the birds], but it really has turned out, after 21 years of data, to be kind of a very unusual circumstance.”

However, it seems as though the “perfect storm” has happened again. On November 28th, 2016, thousands of geese landed on the Pit in the midst of a snowstorm. This time, the number of deaths is not just in the hundreds, but in the thousands.

“I can’t underscore enough how many birds were in the Butte area that night,” Thompson said to the Associated Press. “Numbers beyond anything we’ve ever experienced in our 21 years of monitoring by several orders of magnitude.”

Click here to learn more about the 2016 incident.

The Algae

The following year an algae-covered stick was found floating in the water. This event was shocking because scientists believed that the water was too toxic to host any life.

This stick piqued the interest of Drs. Andrea and Don Stierle, who at that time, were professors at Butte’s Montana Tech. A pair of married microbiologists, the Stierles have spent years studying various environments in search of microbial life with biomedical potential. Today, they work as research professors at the University of Montana in Missoula.

“Euglena algae was the first, to my knowledge, the first organism that was identified in the Pit,” said Dr. Andrea Stierle. “We thought, gosh, if euglena can live there, fungi and bacteria should be able to. So it was that moment that sort of sparked our interest.”

Biological Study

In the video above, Dr. Stierle demonstrates how BP20A, the name she gave the geese yeast, has pulled the metals out of contaminated Berkeley Pit water.

Since then, Drs. Andrea and Don Stierle have been researching the microorganisms that grow in the Pit. In addition to heartier algae, they have found several species of yeast and fungi. Some of these microbes produce compounds with the potential to fight cancer, to help stop inflammation, and to be used as antibiotics. One species of yeast found in the Pit, BP20A, had only been previously found in the rectal swabs of geese. It has the ability to pull 85-95% of toxic heavy metals out of contaminated water. It is only effective in smaller quantities of water, but with a little tweaking, large-scale bioremediation might be possible.

While some of these microbe species are fairly common, growing in such a toxic environment has changed their expression significantly. Cultures from the Pit grown side-by-side with cultures from a biological specimen collection exhibit very different traits, even though they are technically the same species.

The Stierles have found microorganisms with biomedical potential all over the world– from underneath the bark of rainforest trees to within the cells of marine sponges– but they have found that the Berkeley Pit has produced the most abundant source of promising life. The Stierles hypothesize that this is because the acidic conditions in the Pit somewhat mimic diseased human cells. These microbes evolved with their environment itself as the enemy.

A Word of Caution


This strange, anthropogenic landscape has transformed innocuous yeast and fungi into bizarre iterations of their previous forms that produce compounds that are useful in human medicine.

The Pit is a provocative paradox. Humans create a toxic hole in the ground that is acidic enough to kill animals. Yet microbes adapt to this new environment, and even produce compounds that can help us fight disease. However, this odd reaction of nature is no reason to justify the negligence and mismanagement that created the Pit. Yes, certain life forms have adapted to the toxic waters, but others, like the thousands of snow geese, could not.

The complexity of the Pit is arresting. It is a horribly toxic Superfund site that has killed thousands of geese- an environmentalist’s nightmare- but the copper from the Pit helped to build and electrify great American cities, helped to win a world war, and the mining provided jobs for thousands of people.

The Pit is terrifying, though strangely beautiful. It has enabled creation by destruction. It is a killer, and a giver of life.

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