The worlds deepest, biggest and deadliest open pit mines

In this article we will take you to some gigantic man-made holes: open pit mines. We’ll show you the biggest, deepest and deadliest mines in the world. Most of them are located in the United States and can be visited.

You're guaranteed to see some spectacular views, and in the mines that are still active, you'll see rock explosions and mining equipment including some of the biggest dump trucks in the world with capacities exceeding 300 tons and vehicle weights over 1,000,000 pounds (600,000 kg). Even if you have a large pick-up truck, it won't be bigger than a tire of these massive earth-movers. Some mines also have a visitor center or a museum on-site and a few offer tours to the public.

open pit mine
Open pit Mine (Photo by wikipedia)

The biggest iron mine

The worlds biggest open pit iron mine can be found near Hibbing, Minnesota. At its maximum, the area covered by the Hull Rust open pit mine is five miles (8km) long, 2 miles (3,2km) wide and 535 feet (180m) deep. It looks like a man-made Grand Canyon of over 2,000 acres (8,1km²). The first iron ore extractions were made here in 1895. Beginning as a small underground mine, the land eventually became one vast open pit as other mines began to develop and emerge. The center of the actual pit is located where the original town of Hibbing once stood. As the mine grew bigger, the town had to be moved. The move started in 1919 and took two years to complete. 185 houses and 20 businesses were moved a couple of miles to the south. Some of the larger buildings even had to be cut in half before they could be moved. A few remnants of the original town are left near a lookout point at the edge of the mine.

Hull Rust mine
Hull Rust mine (Photo by joukork)

Since the Hull Rust mining operations started 1895, over 530 million tons of waste material and nearly 700 million tons of iron ore have been extracted from the pit. It has been calculated that all the material removed - approximately 1.2 billion gross tons - is equivalent to digging a tunnel through the core of the earth and out the other side. The mine is still operated today by the Hibbing Taconite Company, and taconite pellets are extracted at the rate of 8.2 million tons annually (not counting waste overburden).

Mining excavator
Mining excavator (Photo by not1word)

There is an observation building from where you can overlook the mining activities. A slide presentation explains the history of the mine and early miner's activities. A mine shovel bucket, a mining truck and a walking trail make the trip complete. The mine can be visited from mid-May through September.

The biggest mining operation on Earth can be found in Germany. At the Garzweiler strip mine they remove the top ground layer to extract lignite. The total mining surface is a staggering 18,5 ml² (48 km²) and several villages had to be moved for the mining operation. It is expected to extract 1,3 billion tons of lignite from the mine. After the mine’s depletion, it will be filled with water from nearby rivers, creating Germany’s second largest lake.

Garzweiler mine
Strip mining machines working at the Garzweiler mine

For these amounts of earth moving, you also need some serious machinery. That’s why the Germans created Bagger 288. This 13,500 ton bucket-wheel excavator is the largest land vehicle in the world. Bagger can excavate 240,000 tons of coal or ground a day. The excavator is up to 220 m (721 ft) long and approximately 96 m (315 ft) high.

Bagger 288
Bagger 288 (look at the 2 man at the base of the machine to get an impression of it's size)

The deepest mine

Bingham Canyon Mine, located near Salt Lake City, is the world's deepest man-made open pit excavation. The mine is 2.75 miles (4,5km) across and 0.75 mile (1,2km) deep. Since mining operations started in 1906, Bingham Canyon Mine has been the granddaddy of all copper mines. When you're talking about the actual size of the mine, Bingham Canyon is simply the largest copper mine in the USA. If the mine was a stadium, it could seat nine million people.

Bingham Canyon Mine
Aerial view Bingham Canyon Mine(Photo by Ren Shore)

Bingham Canyon is primarily a copper mine, but it has also yielded a wide range of byproduct metals. These include 620 tons of gold, 5,000 tons of silver, 276 tons of molybdenum and large amounts of platinum and palladium. The Kennecott mining company extracts daily approximately 450,000 tons of rock out of the mine. With these production statistics, it's no wonder that the Bingham Canyon Mine has been nicknamed "the Richest Hole on Earth." The value of metals produced yearly at Bingham Canyon is US$1.8 billion dollars.

Bingham Canyon Mine
Bingham Canyon Mine (Photo by Timjarrett)

Kennecott has built a visitor’s center dedicated to educating the public about mining practices, sustainable development and the importance of mining in modern life. Visitors get breathtaking views and the opportunity to see giant electric shovels fill 320-ton capacity haul trucks that deliver ore to the in-pit crusher. A video, historic photographs and 3D models are also available inside the visitor's center.

Dump truck getting loaded
Dump truck getting loaded (Photo by Caterpillar)

The mine is operating 24 hours per day, 365 days a year. Visitors may come from April 1 through October 31, seven days a week. Entrance fees are $5 for passenger vehicles, $25 for mini tour buses and $50 for tour buses. All entrance fees are donated to charity.

The deadliest mine

Just outside Butte, Montana lies Berkeley Pit: a pit filled with greenish poison a mile and a half wide and over a third of a mile deep. It was once a thriving copper mine where millions of tons of copper ore, silver, gold, and other metals were extracted from the soil.

When underground mining became too costly in the 1950’s, Berkeley Pit became an open pit mine. As the mine grew bigger and deeper, groundwater began to seep into the pit, and pumps had to be installed to keep it from slowly flooding.

Berkeley Pit
Berkeley Pit (Photo by toddtrigsted)

Thirty years later, the mine was so exhausted that it was no longer profitable. The pit was abandoned and the water pumps were shut down. Without the pumps, rain and groundwater gradually began to rise in the pit, leaching out the metals and minerals in the surrounding rock. The water became as acidic as a lemon, creating a toxic mixture of heavy metal poisons such as arsenic, lead, and zinc. No fish live there, and no plants line the shores. There aren’t even any insects around, only some rare kinds of microorganisms survive in the toxic water. The Berkeley Pit had become one of the deadliest places on earth. The iron-rich water near the surface is reddish, yielding to a vibrant lime-green hue not far below the surface, where copper concentrations are higher. If you were to drink large amounts of this water it would kill you by corroding your body from inside.

Berkeley Pit water
Water in Berkeley Pit (Photo by kolopres)

In 1995, a flock of snow geese stopped for a rest at the pond, and 342 of them died there. Authorities use gunshots and loudspeakers to scare away migrating waterfowl, but there have been a few smaller die-offs nonetheless. Sometimes a sinister mist creeps out of the Pit and into the streets of Butte. Citizens are scared about this potentially poisonous fog. The water level is still rising, and if unchecked it will spill over into the area’s groundwater in twenty years. That danger made the area one of the EPA’s largest Superfund sites. Currently, the EPA’s plan is to focus on containment.

Berkeley Pit
Berkeley Pit fog (Photo by toddtrigsted)

The water in the pit is so saturated with metals that Montana Resources Inc. is able to extract copper directly from the water. 13 million gallons (68 million liters) per day, is pumped from the deeper, copper-rich part of the lake to nearby scrap iron holding ponds, causing the copper and iron to swap places. The resulting copper sludge yields up to 180 tons of copper a month. The now iron-rich water is pumped back into the Berkeley Pit, creating the waterfall seen on the northeastern rim. In the meantime, the Pit has become a tourist attraction. There’s a small museum and gift shop located well above the water level. The Berkeley Pit Viewing Stand, open from March until November has an admission fee of $2.

Related articles

Chernobyl after the nuclear disaster

Earth is burning in Centralia

Lake Peigneur, the biggest man-made sinkhole eve made

destination, north america, USA


Our planet made of minerals liquid and fossil fuels created by gravitational pull of our solar system the effect of changing the balance of the earth spinning by excavation possible maybe ? A question that should be addressed spin a ball take a piece from it what happens ? Take away the elements that have put our planet together what happens it can only at the very least make a small impact at the the present but keep doing this and who knows what's going to happen a thought for all

But, we aren't removing the materials from the planet, just relocating them. Also, the quantities of materials removed from even the largest mine have got to be miniscule compared to the mass of the earth. Yes? I have no scientific background, so I'm just guessing, but this seems logical to me.

It depends on net movement closer or farther to the Earth rotation axis that change the rotational speed due to the Coriolis force. In practice, it's the vertical movement and changes in latitude. Filling a formerly empty artificial lake means lifting water that would have flown into the seas - a net lift. Same thing with mines, as rock is pulled up and kept above surface. Those would bring a slowdown of rotation and inevitably also a shift in the earth's axis. But the earth is BIG. Artificial mass movements are minuscule compared to mass movements in earthquakes. Big earthquakes in recent history have shifted the axis by a few inches measured at the pole surface within hours (when the elastic ringing is over).

I once read that if you shrunk the earth down to the size of a squash ball so you could hold in your hand, it would be approximately as smooth as that squash ball. Entire mountains ranges would not even be noticeable. I don't think a few craters here and there will make much difference to its spin.

You are correct and Mr. Durant is wrong.

The earth weighs 6.580 sextillion tons. That's 6,580,000,000,000,000,000,000 tons. A billion tons of ore, if removed from the planet completely, represents 0.000,000,000,658 % of the total, a little over 6 trillionths of one percent.

excavating large chunks of earth would only cause stability problems if either:
A): The chunks are gigantically huge, the bottom 90% has to have LAVA PUMPS and the hole is continent-sized.
B): The chunks are gigantic, but not as big, but mining them out causes a very large chain of directed volcanic or natural uranium explosions to partially fracture the crust with apocalyptic and suddenly disastrous consequences (unlikely).

By the time the first one becomes a problem, we will have advanced enough technology to live in totally inhospitable environments and thrive, we would need our mining equipment to operate while buried in feet. or miles, of liquid rock and metal.

Remember, Earth is 8000 miles wide and weighs about 5,972,000,000,000,000,000,000 tonnes.
Even if mined out a 2000-mile-wide, 100-mile deep cylinder of crust and mantel rock (density~=3.5 tonnes/cubic meter), We would have moved only 0.1% of earth's mass.
At present, the largest mine is not 100 miles deep, but 0.6, not 2000 miles wide, but 2.5, not cylindrical, but conical. It is 1/300,000,000th the size of the mine I described, and 1/300,000,000,000th the size of earth. Every family on earth would need to dig that by themselves in order to deal the damage of the giant I proposed.

Take a bowling ball, scratch it with a saftey pin: not too hard, just enough to be seen if you hold the thing and tilt it towards the light. To scale, you've probably done more damage to the surface of the bowling ball, than such mines do to the earth. Do you think it'll roll differently?

Do you think a bowling ball will fall out of orbit in an perfect f'ing vacuum that contains holds a magnetic field and gravity? We still don't have an effective method of cleaning up current space junk and paint chips. You are unable to grasp the difference between Macro and Micro. Macro is we use 6-12 sized Yosemite Parks to somehow blast 5 to 10% of our ocean into the sun to break orbit. Go stand in the hallway and no bathroom breaks.

I think the ball is gonna stop to spin on that side u take off a piece

Human excavation will NEVER affect the rotation of the earth. The tallest mountains in the world are like microscopic pitting in the surface of a "perfectly" smooth ball bearing when scaled down to that size. Idiocy.

The amount of metals contained within would massively outweigh the amount extracted, that theory is just not feasible. The Iron rich core spins to keep the magnetic field active and the spin of Earth has nothing to do with mineral deposits.

You don't have to worry about the spinning ball question. Moving ore from the ground is not going to have an impact. In fact if you want to see how we know this then take the earth about 10,000 years ago and you would see a gigantic layer of ice that covered most of North America over a mile thick. This weighed down the land so much that when it melted there was actually a rebound of the ground to what we have today. The amount of minerals that are mined would pale in comparison to the weight of that glacier that once sat on North America. Moving minerals from one place to the other is not going to affect the earth's spin. However taking toxic minerals below ground water levels and moving them into our ground water will affect us adversely.

the morenci mine in az is a bigger copper mine than utah.

Morenci isn't larger. It just produces more copper.

that's true arowe

What about this one?

Open Cast mine 2km in Diameter and 898m deep in Phalaborwa South Africa 2km in Diameter and 898m deep

Why isn't the Athabasca tar sands listed here? The operations in Alberta are far more visible from space than most of these mines listed.

The Athabasca OIL sands are shallow and are in a constant state of reclaimation, the land after is as good or better than before extraction

Morecni Mine as whole is larger than any of the above and expanding every day.

I doubt the Hull Rust mine is the largest open pit mine in the world, as it can't be much larger than 25 square km (being 8km long and just over 3km wide).
The lignite open pit mines in Germany are larger. Garzweiler is currently about 48 square km, and Hambach is 33 square km.

You guys are right and the article will be edited accordingly

The Bingham Canyon Mine visitors center is closed until further notice. (The mine collapsed last year.) The mine is still running and are digging it out again, but it may be years before everything is running well enough that they want visitors looking over the edge...

"That danger made the area one of the EPA’s largest Superfund sites."

How come it's not the company that exploited the site that pays for decontamination ???

The Company that mined this area went bankrupt long time ago!

What about the effect of open pit mining on the surface strength and balance of gravity of the earth? I increasing or decreasing even an ounce on a tire can cause problems. So talking millions of tons of dirt from multiple sites probably does something.

Anyone who thinks that mining will have an effect on the rotation of the Earth is an idiot.

You are still on earth are you not.

ya that is true. People have been mining for years but yet the earth have not stopped with its rotation

Just because you saw a science demo about a gravity and space-time = your backyard trampoline getting broken by throwing a 400 kid back and forth.

You do realize that the Meteor that killed the dinosaurs didn't budge the planet? So extinction level events, don't even have a cosmological impact. We could nuke ourselves 500 times over. and still the earth will spin (or another writer "roll"). Until the SUN dies and becomes a Red Giant, then Earth would be swallowed and the assumption is that Mars would be orbiting like Mercury or Venus right now.

I highly believe that the pit should be treated as an emergency!

if we delay treatment for this water, we might cause more harm for ourselves!!

musicians must also campaign for water treatment! they're our voice!

Mining is spectacular. As it disturb a very limited area, it create a lot of job and bring resources to humans. As a minng hydrogeologist, I had the opportunity to visit some of these sites.....and these are close to art. Of course we have to take care about the planet, but this is simply magnificient....

If the lake is like a big lemon, acidic and all, it makes me wonder if electricity could be generated from it just by shoving electrodes down deep in the abyss. Just one big battery.