Disputes between miners' unions and companies continued through the 1920s and 1930s in Butte, with several strikes and protests, one of which lasted for ten months in 1921.
On New Year's Eve 1922, protestors attempted to detonate the Hibernian Hall on Main Street with dynamite.

Further industrial expansions included the arrival of the first mail plane in the city in 1928, and in 1937, the city's streetcar system was dismantled and replaced with bus lines.
After the 1920s, the ACM began to reduce its activities in Butte due to the labor-intensivity of underground mining, as well as competition from other mine holdings in South America.
This ultimately led the Anaconda Company to switch its focus in Butte from underground mining to open pit mining.

Since the 1950s, five major developments in the city have occurred: the Anaconda's decision to begin open-pit mining in the mid-1950s, a series of fires in Butte's business district in the 1970s, a debate over whether to relocate the city's historic business district, a new civic leadership, and the end of copper mining in 1983.
In response, Butte looked for ways to diversify the economy and provide employment.
The legacy of over a century of environmental degradation has, for example, produced some jobs.
Environmental cleanup in Butte, designated a Superfund site, has employed hundreds of people.

Thousands of homes were destroyed in the Meaderville suburb and surrounding areas, McQueen and East Butte, to excavate the Berkeley Pit, which opened in 1954 by Anaconda Copper.
At the time of its opening, the Berkeley Pit was the largest truck-operated open pit copper mine in the United States.
The Berkeley Pit grew with time until it began encroaching on the Columbia Gardens.
After the Gardens caught fire and burned to the ground in November 1973, the Continental Pit was excavated on the former park site.
In 1977, the ARCO (Atlantic Richfield Company) company purchased Anaconda, and only three years later started shutting down mines due to lower metal prices.
In 1983, all mining in the Berkeley Pit was suspended.
The same year, an organization of low income and unemployed residents of Butte formed to fight for jobs and environmental justice; the Butte Community Union produced a detailed plan for community revitalization and won substantial benefits, including a Montana Supreme Court victory striking down as unconstitutional State elimination of welfare benefits.
After mining ceased at the Berkeley Pit, water pumps in nearby mines were also shut down, which resulted in highly acidic water laced with toxic heavy metals filling up the pit.

Anaconda ceased mining at the Continental Pit in 1983.
Montana Resources LLP bought the property and reopened the Continental Pit in 1986.
The company ceased mining in 2000, but resumed in the fall of 2003.

From 1880 through 2005, the mines of the Butte district have produced more than 9.6 million metric tons of copper, 2.1 million metric tons of zinc, 1.6 million metric tons of manganese, 381,000 metric tons of lead, 87,000 metric tons of molybdenum, 715 million troy ounces (22,200 metric tons) of silver, and 2.9 million ounces (90 metric tons) of gold.
Disputes between miners' unions and companies continued through the 1920s and 1930s in Butte, with several strikes and protests, one of which lasted for ten months in 1921. On New Year's Eve 1922, protestors attempted to detonate the Hibernian Hall on Main Street with dynamite.
Further industrial expansions included the arrival of the first mail plane in the city in 1928, and in 1937, the city's streetcar system was dismantled and replaced with bus lines. After the 1920s, the ACM began to reduce its activities in Butte due to the labor-intensivity of underground mining, as well as competition from other mine holdings in South America. This ultimately led the Anaconda Company to switch its focus in Butte from underground mining to open pit mining.
Since the 1950s, five major developments in the city have occurred: the Anaconda's decision to begin open-pit mining in the mid-1950s, a series of fires in Butte's business district in the 1970s, a debate over whether to relocate the city's historic business district, a new civic leadership, and the end of copper mining in 1983. In response, Butte looked for ways to diversify the economy and provide employment. The legacy of over a century of environmental degradation has, for example, produced some jobs. Environmental cleanup in Butte, designated a Superfund site, has employed hundreds of people.
Thousands of homes were destroyed in the Meaderville suburb and surrounding areas, McQueen and East Butte, to excavate the Berkeley Pit, which opened in 1954 by Anaconda Copper. At the time of its opening, the Berkeley Pit was the largest truck-operated open pit copper mine in the United States. The Berkeley Pit grew with time until it began encroaching on the Columbia Gardens. After the Gardens caught fire and burned to the ground in November 1973, the Continental Pit was excavated on the former park site. In 1977, the ARCO (Atlantic Richfield Company) company purchased Anaconda, and only three years later started shutting down mines due to lower metal prices. In 1983, all mining in the Berkeley Pit was suspended. The same year, an organization of low income and unemployed residents of Butte formed to fight for jobs and environmental justice; the Butte Community Union produced a detailed plan for community revitalization and won substantial benefits, including a Montana Supreme Court victory striking down as unconstitutional State elimination of welfare benefits. After mining ceased at the Berkeley Pit, water pumps in nearby mines were also shut down, which resulted in highly acidic water laced with toxic heavy metals filling up the pit.
Anaconda ceased mining at the Continental Pit in 1983. Montana Resources LLP bought the property and reopened the Continental Pit in 1986. The company ceased mining in 2000, but resumed in the fall of 2003.
From 1880 through 2005, the mines of the Butte district have produced more than 9.6 million metric tons of copper, 2.1 million metric tons of zinc, 1.6 million metric tons of manganese, 381,000 metric tons of lead, 87,000 metric tons of molybdenum, 715 million troy ounces (22,200 metric tons) of silver, and 2.9 million ounces (90 metric tons) of gold.
Butte, Montana