How a 1912 Utah copper mine became the deepest, most toxic excavation on Earth

The 1912 Bingham Canyon Mine

Utah Copper and Boston Consolidated Mining Company built the “largest industrial mining complex in the world” by 1912. They merged in 1906 when their digging sites grew close to each other in Bingham Canyon.

ASARCO built a huge smelter nearby to handle the copper coming from the growing pit. These combined mining efforts started a new age in mining that still continues today. The pit keeps growing bigger each year as mining operations continue to extract copper and other metals.

The Decision That Started It All

Daniel C. Jackling saw potential in Bingham Canyon’s vast copper deposits in 1904. Most companies ignored these deposits because they contained only 2% copper, while richer mines had 10-15%.

Jackling convinced investors to back his new approach. He planned to remove entire mountainsides using open-pit mining instead of digging tunnels underground. This required buying expensive steam shovels and building railroads when most mines still used picks and shovels worked by hand.

Steam Shovels That Changed Mining Forever

Huge steam shovels arrived in Bingham Canyon in 1906. Each weighed over 100 tons and ran day and night, replacing hundreds of workers. By 1912, engineers started converting these machines to electricity to work more efficiently.

The early shovels sat on railroad tracks next to train cars they filled with rock. By 1921, Utah Copper had 21 steam shovels working alongside 60 steam locomotives. This machinery transformed the canyon into a constantly moving industrial zone.

The Railroad-Pit Operations System

Railroad tracks ran on multiple levels inside the mine like a giant 3D maze. Each level had its own tracks, with trains hauling copper ore to processing plants and waste rock to dump sites.

Utah Copper built the Bingham & Garfield Railway in 1911 to carry ore between the mine and mills 16 miles away. Trains ran non-stop, day and night. So many trains moved through this short rail line that it became one of America’s busiest railways.

The Massive Scale Of Early Operations

Workers had to remove the worthless rock covering the copper ore first. For every ton of valuable ore, they removed two tons of waste rock. This work began in 1906 with steam shovels stripping away entire hillsides, changing the canyon forever.

Teams worked around the clock to keep up production. By 1921, the mine removed over 300,000 cubic yards of rock every three months. This equals digging up a football field to a depth of 140 feet.

The Immigrant Workforce That Built The Mine

Workers from around the world came to Bingham Canyon for jobs as the mine grew. By 1912, 65% of people living in the canyon were immigrants. The population grew to 15,000 by the early 1920s.

Miners lived in small houses built on steep canyon walls. They spoke many languages, creating a diverse boomtown. Mining companies hired workers from Europe, Asia, and Mexico.

The jobs were dangerous and the housing was basic, but people came for the steady work.

Toxic Materials Used In Early Processing

Workers used asbestos throughout the mining facilities by 1912 to prevent fires. Copper processing requires extreme heat—near 5,000°F—making fire protection essential. No one wore masks or protective gear when handling asbestos.

Tiny asbestos fibers entered workers’ lungs without their knowledge. Processing copper also required chemicals to separate the metal from rock. These chemicals, along with the high heat, created health hazards for everyone nearby.

The Early Environmental Impact

Asbestos fibers from the mine floated into worker housing and nearby towns. These invisible particles caused lung diseases and cancer in many people over time. The mining operations also released arsenic and mercury into the surrounding land and water.

These heavy metals stayed in the soil and water for decades. People living downstream from the mine got sick more often as these toxic substances built up in their communities and drinking water.

The First Environmental Protests

Farmers joined forces against the smelters in 1904-1905 after seeing their crops die. Smoke from the smelters contained sulfur dioxide that killed plants and hurt people’s lungs.

The farmers sued in federal court—one of America’s first environmental lawsuits. In 1906, Judge Marshall ruled that smelters could not process ores containing more than 10% sulfur. This early victory forced mining companies to change how they operated and recognize their impact on nearby farms.

The Beginning Of Corporate Consolidation

Kennecott Copper Corporation bought 25% of Utah Copper in 1915 after seeing how profitable the mine was. By 1923, they owned 75%, taking control of the operation. Bingham Canyon originally had 21 separate mining companies in 1911.

Through mergers and buyouts, these were reduced to just two companies by 1970. This trend put more power in fewer hands while making the mining process more efficient and profitable for the remaining companies.

The Birth Of The World’s Largest Excavation

The open-pit mining at Bingham Canyon created what would become Earth’s largest human-made hole. Engineers designed the pit to grow wider and deeper as mining continued.

Today the pit measures over 3/4 mile deep and 2.5 miles wide, covering 1,900 acres. Decades of digging produced more than 19 million tons of copper, making it the most productive copper mine ever.

The pit is so massive that astronauts can see it from space without telescopes.

Visiting Bingham Canyon Mine overlook

The Bingham Canyon Mine Visitor Experience is located southwest of Salt Lake City in the Oquirrh Mountains. Rio Tinto Kennecott reopened the visitor center for the 2025 season in May, after previous closures due to landslides.

Tickets cost $6 per person (children under 5 are free) and must be booked ahead online. All ticket money goes to the Kennecott Charitable Foundation that supports local non-profits.

Shuttle buses run every 30 minutes from 9:30 AM to 2:30 PM, seven days a week. The entire experience takes about an hour. At the overlook, you can see the massive 2.5-mile-wide, 0.75-mile-deep pit that’s visible from space.

The experience includes exhibits about mining history, full-size mining equipment you can walk inside, and panoramic views of ongoing operations. Photography is allowed, but professional photography is not permitted.

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