Coming over the hill on Highway 1806 in late October, the sprawling Standing Rock encampment surged into view. Tipis, tents, and a geodesic dome dotted the valley below. Nestled along the Cannon Ball and Missouri Rivers in remote North Dakota, the Oceti Sakowin camp had recently grown to over 7,000 people.

Those camped there have led a months-long effort to resist the construction of the Dakota Access Pipeline. The 1,170-mile pipeline is slated to transport crude oil from the Bakken shale fields of North Dakota, through Standing Rock Sioux treaty land, under the Missouri River, and on to Illinois. The Standing Rock “water protectors,” however, fear that the pipeline will poison the river and with it, the water supply not only for the Standing Rock Sioux but the millions of others who live downstream. And so they pray and march and refuse to move. So far, their efforts have managed to halt the pipeline’s advance at the west bank of the Missouri pending a final permit from the Army Corps of Engineers.

By the time I arrived, the Oceti Sakowin camp had been inundated by supporters from across the country: from the environmental movement, Black Lives Matter, the progressive media, and elsewhere. Yet the Standing Rock struggle remains an indigenous-led one, an historic coming together of first nations. It’s the first time the seven bands of the Great Sioux Nation have united since Custer was defeated 140 years ago, and with more than 300 nations standing in official solidarity with the movement, it is by far the largest mobilization of indigenous peoples in the United States in a generation or more. As we drove up to the front gate, the security team that waved us through was a mix of old-timers with American Indian Movement logos safety-pinned to their leather coats and the next generation of indigenous youth from Standing Rock.

The 10 days I was at the camp, which included the presidential election, were a period of relative calm, as the pictures in the accompanying photo essay suggest. The Army Corps of Engineers was set to announce a major decision on whether to grant an easement to allow Energy Transfer Partners to drill below the Missouri river, and the indigenous leadership wanted to keep prayer-based actions outside of camp to a minimum pending the decision.

Those who were digging in for the long haul used the respite to prepare for winter by gathering necessary supplies and winterizing their shelters. Each night, temperatures plummeted, a dusting of white frost blanketing the tents. Every morning without fail, a voice would come over the loudspeaker in the pre-dawn darkness, announcing: “It’s time to get up. This is not a vacation. We’ve got work to do, relatives.”

This was also a time of prayer and ceremony, which people at camp described as part of an essential process of personal and collective healing, helping them to stay strong in the face of the long struggle ahead. Even the marches and demonstrations were always peaceful and prayer-inflected.

This period of relative tranquility, however, was broken this past Sunday as police from the Morton County Sheriff’s Department confronted some 400 water protectors on Backwater Bridge just north of camp. According to a report from Dallas Goldtooth, an organizer with the Indigenous Environmental Network, the protectors were attempting peacefully to move a burned-out truck off the bridge and clear access to the public roadway when police trapped them on the bridge and opened fire with tear gas, rubber bullets, mace canisters, and concussion grenades.

Jerky video from the scene shot by witness Kevin Gilbertt shows the police blasting water cannons into the crowd in sub-freezing temperatures. People lost consciousness and dropped to the ground as the freezing water hit; an elder went into cardiac arrest and was revived on site by medics, according to a press release issued by the Standing Rock Medic and Healer Council. It also reports that at least 300 people were injured, with 26 people requiring immediate hospitalization. One of them, Sophia Walinsky, is facing amputation after a concussion grenade reportedly exploded on her left arm.

While this level of brutality and violence against peaceful demonstrators is clearly extreme, it was not the first time the water protectors have been met by blunt force and intimidation. Nor is it likely to be the last. Native peoples in this country have faced every tool the US government has to displace, dispossess, and destroy them for more than 500 years.

Yet as the winter comes, the water protectors are not giving up. Their movement is part of a long history of struggle. And regardless of what brutal force it faces, it isn’t going away.

The bright flags of more than 300 first nations line the road into the Oceti Sakowin camp, among them the flags of the Red Lake Nation of Chippewa in Minnesota, the Curve Lake First Nation of the Ojibwe near Ontario, the Lumbee Tribe of North Carolina, the Spirit Lake Nation Sioux from North Dakota, and others. (Jake Ratner.)

Mni wiconi, translated as "water is life," can often be heard ringing out throughout camp as groups huddled around fires spontaneously shout it into the night and others pick up the call, echoing it back. While the standoff at Standing Rock has been a fight for sacred land and indigenous sovereignty, it’s also part of global movements to protect the planet’s water. (Jake Ratner.)

As temperatures dip below freezing and the wind sweeps across the open plain, deliveries of firewood, stoves, tipis, and yurts stream into camp, donated by other first nations and supporters from around the county. The North Dakota winter is on its way, but many of the water protectors have no intention of leaving until the pipeline is stopped. (Jake Ratner.)

Between the sounds of generators humming and wood splitting, helicopters whirring and people hammering, there are quiet moments, too. As the sun dips behind the horizon one evening, people gather for a peaceful moment, followed by prayer at the sacred fire or participation in a sweat ceremony. (Jake Ratner.)

As people wrap up the day’s work, they head to the communal kitchens for a hot meal, congregate around the sacred fire to hear songs and drumming, or come together for quiet strategy meetings that run late into the night. (Jake Ratner.)

Sunset at the Oceti Sakowin camp, which sits atop 1851 treaty land that was seized by the Army Corps after the completion of the Ohae Dam in the early 1960s. Many elders carry childhood memories of when the dam was built, flooding the tribe’s most valuable rangelands, forests, and farms. (Jake Ratner.)

Lyle Uses Arrow, a Standing Rock Sioux elder, stands atop a hill overlooking the site of his family's old ranch, which was flooded by the Ohae Dam project. Speaking about the 50,000 acres of tribal land lost, he says: “They said it was beautiful. They said birds were singing there all the time and there was a forest of cottonwood. There was wildlife.” (Jake Ratner.)

Heavily armed riot police arrive at the hillside opposite the Oceti Sakowin camp on November 7th to intimidate a group of water protectors who have made their way to the slopes to pray. The Morton County Sheriff’s department has responded to the peaceful demonstrations with increasingly violent force, prompting the United Nations to begin an investigation into human rights abuses committed by the police, including "excessive force, unlawful arrests, and mistreatment in jail.” (Jake Ratner.)

A crowd of water protectors face a rogue gunman on November 12th during a prayer march near Mandan, ND. The gunman—an irate white man in a truck—has surprised them as they march on a dusty road; without provocation, squeezes off seven loud rounds into the air. (Jake Ratner.)

One of several bullet casings scattered on the ground after the gunman drives away. (Jake Ratner.)

Jumoke Emery-Brown, representing Black Lives Matter, raises his voice for Standing Rock. “We will not be moved. We will not be poisoned. We will not be destroyed. We stand here today as representatives of ancestors you could not kill. We are here and you will see us. And we will be free.” (Jake Ratner.)

On November 14th, over 400 people take to the streets of Bismarck, fanning out in the four cardinal directions to surround the state capital building, triggering a soft lockdown at the capital. (Jake Ratner.)

Thomas H. Joseph II of PICO LA RED speaks to the crowd in front of the capital. "We will come in a peaceful and prayerful manner," he says. "We will continue to move in this way as people across this nation stand united with Standing Rock. People of all faiths, all colors, have come to stand with Standing Rock. And this movement will continue to grow and move. We will be successful. We will win. We are winning.” (Jake Ratner.)