Montanakids | Future of Mining

For more than 150 years, mining has shaped Montana's towns, people, and landscapes-and it will keep doing so in new ways.

Today, Montanans are working to balance the need for metals and jobs with the need for clean water, safe communities, and healthy wildlife.

The Berkeley Pit: from mine to giant "lab"

In 1955, the Berkeley Pit open-pit copper mine opened on Butte's "Hill," replacing many of the older underground mines.

Mining there stopped in 1982, leaving behind a huge pit about 1,600 feet deep that is now partly filled with about 900 feet of water.

After mine pumps were shut off, groundwater began to rise and filled the pit, creating the Berkeley Pit Lake. The water is acidic and contains dissolved metals like copper, zinc, and arsenic, which makes it unsafe for drinking or irrigation.

Scientists and engineers closely track a "protective water level" of 5,410 feet above sea level-the height where contaminated water could start moving out of the pit toward other waters. As of early 2025, the pit's water level is about 5,355.7 feet, still safely below that limit.

Keeping the pit from overflowing

The Horseshoe Bend Water Treatment Plant pumps and treats millions of gallons of mine water each day.

To make sure the Berkeley Pit never overflows, companies responsible for the site-Montana Resources and Atlantic Richfield (ARCO)-must pump and treat water before it reaches the protective level.

The Horseshoe Bend Water Treatment Plant can treat about 7 million gallons of water per day, removing metals and neutralizing acidity so the discharged water meets state and federal standards before it flows into Silver Bow Creek.

Since regular pumping and treatment began in 2019, more than 9 billion gallons of water have been treated and released by April 2025, keeping the pit's water level nearly steady instead of rising 6-7 feet each year.

Scientists are also studying biological methods-using certain bacteria, algae, and other organisms-to help clean contaminated mine waters, turning the pit into a kind of outdoor laboratory for future cleanup projects.

Superfund and lessons from the past

The Berkeley Pit and surrounding mine-flooding system are part of one of the nation's largest Superfund cleanup areas, which also includes stretches of Silver Bow Creek and the Clark Fork River.

Cleanup work includes managing contaminated water, removing or safely covering mine waste, and restoring land and streams as much as possible.

Problems from older mining-before strong environmental laws existed-helped Montanans realize that mine plans must include bonding, water treatment, and long-term monitoring. These lessons now shape how new mines are permitted and operated.

Cyanide heap-leach mining and Initiative 137

In the late 1900s, some Montana gold and silver mines used cyanide heap-leach methods, where cyanide solution is sprayed over piles of crushed ore to dissolve precious metals.

Cyanide is highly toxic, and spills or leaks at these mines raised serious concerns for fish, wildlife, and drinking water.

In 1998, Montana voters passed Initiative 137, which banned new open-pit gold and silver mines that use cyanide heap or vat leaching and stopped existing cyanide operations from expanding their pits. A few older mines were "grandfathered" under the law.

Montana became the first U.S. state to adopt such a ban, showing strong public support for stricter environmental protections in hard-rock mining.

New mining and critical minerals

Underground miners at a platinum-group metals (PGM) operation in south-central Montana.

Today's Montana mines are fewer in number but often larger and more mechanized, using more machines and fewer workers to move bigger volumes of rock.

In south-central Montana, the Stillwater and East Boulder mines and the Columbus Metallurgical Complex produce palladium and platinum-metals used in catalytic converters, some fuel cells, and electronics.

These platinum-group metals are considered "critical minerals" for the United States, and Montana is home to the nation's only primary source of them.

Global markets can still shake local communities: increased palladium exports from Russia and other countries have pressured prices and contributed to job cuts of several hundred workers at Montana's PGM operations in recent years.

Communities, conservation, and citizen groups

Many Montanans still rely on mining and related industries for high-paying jobs, especially in places like Butte and Stillwater County.

At the same time, people also value clean rivers, outdoor recreation, and tourism, which depend on healthy landscapes and wildlife.

Citizen groups, tribal nations, landowners, and local governments often take part in permit hearings, public-comment periods, and court cases about new or expanding mines, pushing for strong bonding, careful reclamation, and long-term monitoring to protect water and land.

What the future may look like

In the future, mining in Montana will likely focus more on critical minerals like copper and platinum-group metals needed for electric vehicles, clean-energy technologies, and electronics.

New and existing mines will rely on better water-treatment systems, more detailed reclamation plans, and stricter bonding requirements to cover cleanup costs.

Any large new mine is likely to face careful review, especially near important rivers, wildlife habitat, or communities that depend on agriculture and tourism.

Most experts agree mining will not disappear from Montana, but its future will depend on strong laws, community involvement, company practices, and new science that helps clean up old messes while reducing the impact of new projects.

Agriculture & Business

Future of Mining in Montana

Future of Mining