Mining and Remediation

As early as the 1860s, prospectors began flocking to the Summit Valley in Southwest Montana in search of wealth and opportunity. In Butte they found the “richest hill on earth” with a massive ore body that would eventually support an industrial revolution and help America and its allies win two world wars.

Butte began as a mining camp in the 1860s when the first prospectors found gold in and around Silver Bow Creek. Silver milling began in the 1870s and continued on a large scale into the 1890s, booming during the era when U.S. currency was backed by silver as well as gold. During this era, Congress enacted laws that required the U.S. Treasury to purchase large amounts of silver, a substantial portion of which was mined and milled in Butte. Much of this early mining activity occurred on land owned by the U.S. government, which would not be conveyed to private owners until later. Copper mining and milling began in this same era, much of it also on public land, and copper would become the metal that has sustained Butte’s industrial history for more than a century.

Butte’s Mining Heyday

Copper ore (and other ore containing minerals like silver, zinc and manganese) from the Butte-area mines was milled and smelted locally in Butte between the late 1800s and mid-1940s, in over 20 separate historic processing facilities. The first crude smelter was built in approximately 1867 to treat the rich copper ore from the Parrot mine. It was built by Dennis Leary, an Irishman, and three other individuals. Prior to the erection of the first smelter (and for some time thereafter) ore extracted from Butte mines was transported long distances to facilities to be smelted, some as far away as Swansea, Wales and Freiberg, Germany.

In the late 1800s and early 1900s, the processing height of Butte’s copper smelters, Butte workers were producing the key component in electrical wire just at the time the nation’s rapid electrification was driving up prices and demand. At this time, five large operations dominated the copper smelting business in Butte: the Parrot, the Butte Reduction Works (BRW), the Colorado, the Butte & Boston, and the Montana Ore Purchasing Company (MOPCo).

In the early 1900s, the Montana School of Mines ran its own mill and concentrator to teach its students the latest mineral processing technologies. After the turn of the century, other copper processing operations were established in Butte, including the Pittsmont, the Bullwhacker and the Butte & Duluth. Zinc mining and milling boomed in the early 1900s, with leading zinc processors including the Butte and Superior and the Timber Butte.

The Anaconda Copper Mining Company (ACMC, subsequently renamed “The Anaconda Company”) was incorporated in 1895. ACMC and its successor, the Atlantic Richfield Company, never operated a copper smelter or silver mill in Butte; instead the company shipped its ore elsewhere by railroad for smelting and refining. Its principal smelting and refining facilities were located at Anaconda, approximately 25 miles west of Butte, and Great Falls, approximately 150 miles to the northeast.

During the Centennial Exposition in Philadelphia in 1876, Alexander Graham Bell transmitted speech through a copper wire. His invention became the telephone. Not long after, in 1879, Thomas Edison lit the streets of New York with an early electric power system and electric light bulbs, portending a day when millions of miles of copper wiring would be needed to supply electricity throughout the U.S. and to manufacture the lighting, appliances, motors, and other products that would be powered by electricity Thus, although most of the copper smelters in Butte closed by 1910, copper mining continued and expanded, fueled by growing industrial and consumer needs.

After 1930, until the Weed Concentrator began operations in 1963, the only large commercial mineral processing operation in Butte was a manganese nodulizing plant in the grounds of the Butte Reduction Works. The Domestic Manganese and Development Company’s plant started up in 1928, and its operations were expanded in connection with U.S. government operations during World War II by the addition of a manganese concentrator. The U.S. continued to store manganese on site until the last government stockpiles were removed in 1992 by the U.S. Bureau of Reclamation.

Throughout the years between 1895 and the early 1980’s, ACMC and the Anaconda Company continued to mine copper. The company expanded the extensive network of underground mine workings that it mined into the 1970s. The company began excavating an open pit mine known as the Berkeley Pit in 1955, and it later began excavating a second open pit mine known as the East Berkeley Pit (now known as the “Continental Pit”) to recover lower grade copper ore and molybdenum.

The Anaconda Company had willing governmental partners in its endeavors—both the State of Montana and the United States of America. For example, a 1910 decision of the Montana Supreme Court explained that but for the mineral industry, “portions of our state would be almost entirely destitute of population, whereas they now furnish homes and the means of support for populous communities. Hence, from the beginning it has been the policy of the state, indicated by its constitutional and statute law, as interpreted by this court, to foster and encourage the development of this state’s mineral resources in every reasonable way.”

On the federal front, the U.S. government supported, encouraged and facilitated the minerals industry in Butte during both times of peace and war. During the era of the Great Depression, various federal agencies (including the Federal Emergency Relief Administration [FERA] and the Works Progress Administration [WPA]), funded and facilitated the rechannelization and riprapping of Silver Bow Creek to reduce accumulations of eroded sediment, mining-related waste, stormwater, sewage and debris that contributed to frequent flooding, and to provide a straighter creek channel to make it a more effective conveyor such wastes downstream and out of Butte. When Montana first classified its waterbodies in the 1950’s according to their existing use, and the future uses they could support, the state recognized that Silver Bow Creek was being used for waste disposal. As late as 1967, the Federal Water Pollution Control Administration continued “to permit the continued use of Silver Bow Creek for waste transport” downstream to “a series of treatment ponds” now known as the Warm Springs Ponds.

Copper produced in the Butte mines was needed and used to help bring electric power and telephone service to homes throughout the country. The period of rapid electrification in the U.S. began in the 1890s, and peaked in the 1920s. In 1935, President Franklin Roosevelt created the Rural Electrification Administration by executive order, which Congress then ratified in the Rural Electrification and Telephone Service Act of 1936, to bring electricity and telephone service to unserved rural communities. Copper was a necessary element to implement this law, and other federal policies. This state and federal support and encouragement of the metals industry would continue throughout the Cold War era and in some ways continues today. 

During times of war, minerals from Butte were crucial to the war effort. In both World War I and World War II, Butte produced the copper and other metals that the U.S. and its allies needed to win both wars. In the World War II era, “demand for copper and other minerals soared due to their use in critical components of airplanes, ships, tanks, bomb sights, ammunition and an astonishing range of other types of equipment.”Both the U.S. War Industries Board (in World War I) and the U.S. War Production Board (in World War II) relied on operations in Butte and Anaconda to produce these metals.

The nation also depended on Butte to produce a significant share of the copper and other metals that ushered in the modern industrial age. Starting during the late 19th and early 20th century, Butte drew people from all over the world (including Ireland, Cornwall, Wales, Scotland, Slovenia, Slovakia, Serbia, Croatia, Hungary, Germany, Italy, Greece, Finland, Sweden, Norway, Lebanon, Syria, Afghanistan, Mexico and China) who were looking for employment at a decent wage and the opportunity to build a new life. Butte’s multi-national workforce produced the metals the nation needed, and that workforce raised families and created a diverse community on the Butte Hill and surrounding areas whose descendants help make Butte the vibrant city it is today.

According to a 2006 paper, “Butte, A World Class Ore Deposit” by Steve J. Czehura, the former manager of geology and engineering for Montana Resources, huge commercial quantities of ore—including copper, zinc, manganese, lead, molybdenum, silver and gold—have been pulled from the Butte Hill, sustaining generations of dedicated miners and the Butte Silver-Bow community. Approximately 21.5 billion pounds of copper alone were produced from 1880 through 2004.

Atlantic Richfield Company purchased the Anaconda Company in 1977, then merged with it four years later, acquiring at the same time the Anaconda Company’s operations in Butte.

In 1983, Atlantic Richfield suspended its mining activities in Butte, and in 1985 it sold its mining properties in Butte and the surrounding area. Today Montana Resources continues to mine copper and molybdenum in a portion of this area at the Continental Pit.

Addressing a mining legacy through remediation

Past methods of underground and open pit mining, and the processes employed to extract and produce the saleable metals from the ore, altered the landscape and left behind waste generated in mining, milling, and smelting operations that ceased decades ago.

Because the town of Butte grew above and around the mines, much of the Butte Priority Soils Operable Unit’s (BPSOU’s) remediation work has to be undertaken in an urban area.

Following the passage of the Comprehensive Environmental Response, Compensation, and Liability Act ([CERCLA], also known as the “Superfund law”) by Congress in 1980, Atlantic Richfield began working under the direction of the U.S. EPA, and in cooperation with the Montana Department of Environmental Quality (DEQ) and the Butte-Silver Bow Consolidated City and County government (BSB), to investigate and remediate contamination in BPSOU that was impacted by former mining, milling and smelting operations. BPSOU encompasses more than six square miles, over 4,000 acres, across the Butte Hill.

In this process, Atlantic Richfield applied innovative technologies toward the remediation and redevelopment of former mining areas. In geographic terms alone, the scope of the work has been extensive, and the technical issues have been complex. Despite those challenges, great progress has been made. Large parts of the historic mining district have been remediated, reclaimed, and transformed from barren land with no vegetation or commercial activity, into green hillsides planted with native grasses and shrubs, many with interpretative signs, small parking areas and paved trails for public access.

The quality of Silver Bow Creek has also improved substantially since remediation began. Many acres of impacted land have been remediated and made available for public use, including the Copper Mountain Sports Complex, Granite Mountain Memorial Area, and Mountain Con Trail at Foreman Park. Additional remedies have also been completed or are underway.

In April 2019, U.S. EPA released a revised proposed remedy for BPSOU, and following public comments, on February 4, 2020, US EPA issued a modified remedy that will provide a path to complete the environmental remediation chapter of Butte’s history. On February 13, 2020, the U.S. EPA, the State, local Butte-Silver Bow government and Atlantic Richfield Company announced a proposed partial consent decree to implement portions of the BPSOU remedy. Further information about the proposal is on the Completing the Remedy page of this website.

A copy of the proposed Consent Decree is on the Consent Decree page of this website.

To learn more about the Butte Priority Soils Operable Unit, visit the About page!

Check out the full timeline for more information on the history of mining and remediation in Butte.

Butte Treatment Lagoons

Highlights of Remediation Work in Butte

  • More than 400 acres of land within the BPSOU area were addressed through response actions prior to the 2006 EPA proposed plan and additional reclamation is ongoing.
  • Since beginning work in 1988 more than 8 million cubic yards of mine waste and tailings reclaimed or removed – including 1.2 million cubic yards of tailings removed from the banks of Silver Bow Creek.
  • More than one mile of Silver Bow Creek remediated and reconstructed between 1995 and 1998.
  • As of August 2019, the Residential Metals Abatement Program (RMAP) has assessed 3495 residential properties795 attics have been remediated; 484 yards have been remediated; 150 lead-based paint projects have been completed.
  • Since 2009, approximately 8.2 billion gallons of impacted groundwater have been collected and treated.
  • From 2009 to 2017 Butte Treatment Lagoons treated between 600 and 675 million gallons of groundwater per year. The current treatment rate is 630 million gallons per year. Since 1998, billions of gallons of impacted groundwater have been collected and treated.
  • In 2018, more than 1.5 million gallons of clean water were released to Silver Bow Creek on a daily basis.
  • 180 pounds of arsenic, cadmium, copper, lead, zinc, and iron are removed from contaminated groundwater daily.