Police enforce the state of emergency in Cajamarca, Peru, by using tear gas and beating people in the streets following the deaths of three demonstrators in a nearby town on Tuesday. Photos by Ron Haviv/VII

Editor's note: Peru's government declared a state of emergency this week after protests against a gold and copper mining project claimed three lives on Tuesday [update: the death toll has since risen to five] and left at least 21 people injured, prompting a police crackdown. A prominent anti-mining activist says police arrested and beat him in the wake of the demonstrations. OnEarth executive editor George Black and freelance photographer Ron Haviv, reporting a story on the global mining boom, were the only foreign journalists in the region to witness the violence. They filed this exclusive report.

No one, not even those who reap the profits, could claim that a modern gold mine is a thing of beauty. Here in Peru, sadly, it has become a thing of violence.

But let’s start with the physical ugliness. Yanacocha is the biggest gold mine in South America. Majority-owned by the Denver-based mining giant Newmont, Yanacocha begins about 20 miles north of Cajamarca, a city of about 200,000 people in the Peruvian Andes. It’s easy to tell when you’re getting close to the mine, because all of a sudden the twisting, bumpy road turns as if by magic into a two-lane blacktop, with yellow center lines, cat’s eyes, guard rails, white marker posts, signs that tell you not to use your cell phone while you’re driving and that seat belts can save your life. The mine complex stretches for miles, the road bordered with plastic-lined tailings ponds; naked pits hundreds of yards wide and hundreds of feet deep, in which giant haul trucks and other heavy machines labor back and forth like slow-witted ants; and mountainous terraced “heap leach” piles of crushed rock, layer cakes of orange, beige, gray, and rust-red. Black tubing runs up the sides, dripping a sodium cyanide solution into the pile to extract the flecks of gold from the raw rock.

Now Newmont wants to build an even bigger mine, Conga, a $4.8 billion investment, just a few miles away, 12,000 feet up in a pristine landscape of bare mountains and rock walls, sparkling lakes, wetlands, and small streams.

The expansion of mega-mines in the developing world, driven by our insatiable hunger for minerals and the rising price of gold and other metals, is producing an unholy mix of environmental damage and social conflict, and Conga is the perfect illustration of the problem. Protests against the mine have been simmering for months; fortuitously, I arrived in Cajamarca just as they finally boiled over.

The photographer Ron Haviv and I were the only foreign journalists here to witness these events. Ron is one of the best-known war photographers of his generation, and a gold mine in the Andes must have seemed at first like a tame assignment for someone who has spent 20 years working in the former Yugoslavia, Liberia, Iraq, Afghanistan, and many other hot spots. But by the time we’d spent three days in Cajamarca, comparisons with Bosnia did not seem entirely out of place.

We found the town in turmoil. After months of contentious debate, Peruvian president Ollanta Humala announced last week that Conga would go ahead, albeit with some new conditions that were supposed to (but didn’t) mollify its opponents. The walls of the narrow colonial streets of Cajamarca were splotched everywhere with graffiti that said Conga No Va! -- roughly translatable as No to Conga! or Conga Go Home! The handsome cathedral was home to a kind of Occupy Cajamarca! encampment. Hundreds of peasants from the area that will be directly affected by the new mine were hunkered down on mattresses in the cathedral precincts. Hunger strikers from the National University were camped out in pup tents.

On our second morning, thousands of demonstrators flooded the streets. The most remarkable thing was that so many of them were peasant women, wearing the colorful multi-layered skirts and high-crowned white straw hats of the region. Ron moved in and out of the crowd, capturing faces that were contorted with anger and others that seemed exultant at their sheer numbers and the brief, illusory, sense of power. One of the most frequent chants summed up the elemental, and probably irreconcilable simplicity of the dispute: Agua Si, Oro No! Water Yes, Gold No! Water -- billions of gallons of the stuff to wash the ore, to dilute the lethal cyanide solution that extracts the precious metal, is the main requirement of a giant gold mine. Newmont intends to appropriate four high-altitude lakes -- draining two to get at the gold that lies beneath them, using two others to accommodate the mine tailings, and replacing them with a series of man-made reservoirs. The problem is that water is also the main requirement of a peasant farmer, and the four lakes that Conga will destroy sit on the headwaters of five river systems that nourish agriculture in the surrounding area.

Later that day, I posed the same question -- how will this end? -- to two very different people. One was a priest named Marco Arana, who has been one of the animating spirits of the protests [Ed.'s note: Arana was reportedly arrested and beaten by police after the violence]; the other was an official of the Grupo Norte, a consortium of big mining companies who aspire to transform the entire department of Cajamarca into one of the greatest mineral-extraction complexes in the world. Each of them laid out the same three scenarios: Newmont would find the political cost of the conflict too great to bear and take its business elsewhere (possible but unlikely); the protestors would run out of steam as the weeks wore on and abandon their fight (ditto); or the whole thing would end in violence.

Next morning we went to see the Conga mine site for ourselves. To our surprise, the first checkpoint was a breeze. A guard from Securitas, the giant private security firm based in Sweden, waved us through after a perfunctory check of our driver’s ID, as a knot of a dozen police stood off at a distance, clad all in black with ski caps, holding machine pistols. For the next hour or so we we drove slowly around the site, unmolested, getting out periodically for Ron to take photographs. But the trouble began at the second checkpoint. This time the guard questioned us for more than half an hour and made phone calls to his superiors. I decided to play our strongest card, describing my conversation the previous evening with the man from Grupo Norte and saying how impressed I had been by his Power Point presentation with its pie charts and bar graphs showing all the social benefits the mine would bring to this impoverished area. Finally, reluctantly, the guard raised the barred gate to let us through.

Just outside the boundary of Newmont’s property, we stopped for lunch at the home of a campesino on the shoulder of a bowl-shaped valley. He took us to see a spring seep on the slope below his house. He had dug a four-foot-deep concrete-lined tank, a captación, to capture the flow. The idea was that when the water filled the tank to the brim it would run down into a pair of narrow earthen irrigation canals. There were only about four inches of water in the tank, and the six-month dry season had just begun. A small frog lay dead on its back on the floating bed of algae. There used to be hundreds of frogs here, the man told me. Now there were hardly any. The spring started to run dry about six years ago, he said, immediately after Newmont started to sink its exploratory underground wells. His sister was crouched 50 yards away, electric blue skirts billowing over her Wellington boots, scooping out black mud from one of the irrigation channels with her bare hands to allow a trickle of water to flow. She stood up, glaring, and launched into a tirade against the evils of the mine.

We headed back to the second checkpoint in the middle of the afternoon and asked them to raise the barrier again so that we could retrace our steps to Cajamarca. But the mood had hardened. The head of security was called in. We were ordered to leave in summary fashion, and told that we would have to return to Cajamarca by a rough, circuitous road through the mountains.

It was dark by the time we got back. As we approached the town, the driver’s cell phone rang. I saw him frown. Later we put two and two together; the guards at the mine had obviously received a similar phone call while we were eating lunch at the campesino’s house.

The driver said, “Two dead?”

Actually it turned out to be three, with more than 20 wounded. A protest against the mine in the nearby town of Celendín had turned ugly, and police had opened fire on the demonstrators. One of the dead was a boy of 17.

We found Cajamarca seething with rage. A large crowd of mourners was screaming at a phalanx of police with helmets and riot shields. Someone had lit a row of candles on the sidewalk, mourners on one side, police on the other. A young girl next to me was weeping on a friend’s shoulder. She told me that the 17-year-old in Celendín had been a friend of hers.

Events unraveled rapidly. More riot police blocked off the streets leading to the plaza. The inevitable groups of infuriated young men charged the police lines. Tear gas canisters rained down on us. Ron produced a small jar of Vick’s Vapor Rub, which is more effective against tear gas than the vinegar that sympathetic residents were tossing down to the young men from their wooden balconies. Amid the chaos, a small cluster of about 40 people, led by Marco Arana, the priest I’d interviewed the day before, sat cross-legged on the sidewalk holding candles and singing The Sound of Silence in Spanish. Hello darkness, my old friend.

Eventually we retreated to the edge of the plaza, by the Iglesia San Francisco, and watched as white pickup trucks loaded with police slowly circled the square. A man who works for a local human rights organization pointed to the license plates and told me that the vehicles belonged to Newmont. One of the pickups slowed down as it passed the church. A policeman pointed his tear gas pistol directly at me, and screamed at us to go home. Back at the hotel, we found out that the government had declared a state of emergency, to take effect at midnight.

I left Cajamarca early this morning, the Fourth of July, heading for Bogotá and an appointment to interview officials from AngloGold Ashanti, which plans to build a multi-billion-dollar gold mine in the Colombian province of Tolima. Appropriately, it is known as La Colosa. Last month, 20,000 people took to the streets of Ibagué, the provincial capital. I wondered if the news from Cajamarca had reached them yet.

As we taxied for takeoff, I saw a column of two dozen soldiers in camouflage uniform making their way to the small terminal building. But that was not the image that lingered as the plane rose into the blue Andean sky. What stayed in my mind was the teenage girl weeping on her friend’s shoulder, and the tiny, pallid body of the frog lying dead by the dried-up spring.

George Black’s article on the global gold-mining boom will appear in a future edition of OnEarth magazine. Click here to subscribe and support OnEarth's nonprofit journalism.