Months after it began, the fight against the Dakota Access Pipeline continues here at the confluence of the Cannonball and Missouri Rivers.
Driving down from the high plains to the camp on the river banks, the view is vast and moving. People on horseback canter by and thousands of colourful flags flutter in the prairie wind.
What was a rough encampment is looking increasingly permanent as protesters - they prefer the name "water protectors" - dig in for winter. There are sturdy wooden buildings now, Mongolian yurts, and wall tents with wood stoves and even a geodesic dome where meetings and spiritual instruction take place.
The Standing Rock Sioux nation, whose territory is all around here, are leading this action and their elders set the tone. Newcomers are welcome but they have to take an orientation course where they learn about non-violence, the ways of the Sioux, and the sacred camp fires around the grounds that must be respected, never photographed or allowed to go out.
|What was a rough encampment is looking increasingly permanent as protesters dig in for winter [Reuters]|
At the northern end, beneath a line of hills where police vehicles and spotlights mark the proposed path of the pipeline, there are daily courses in "non-violent direct action", led by experienced protesters from other parts of the United States.
One of those was going on as we wandered the camp, mostly trying to keep warm in the blowing snow and icy winds.
A ring of people stood in open ground and two instructors, from Hawaii and Alaska, showed them how to avoid violent confrontation during protest actions while still holding their ground and standing firm for their beliefs.
"If they [police] pull you from the line, let them, and everyone else just close up, lock arms and keep chanting, praying, singing, whatever. Never scream or swear or at them," said the instructor, a military veteran.
"If they arrest you, we've got legal people who can help."
It's helpful advice. More than 500 demonstrators have been arrested since the camp began last summer. Among them are celebrities, journalists and many Native American activists. North Dakota newspapers have reported the local court system is being strained beyond its capacity by all the trials and arraignments, which usually seem to end in a dismissal or reduction of charges.
There have been ugly confrontations and both sides blame each other. In the early days of the protest, last September, there were reports of vandalism and deliberately set fires, but lately much of the violence seems to have come from the authorities.
In late November, a group of protesters trying to cross a bridge blockaded by police just outside the camp faced water cannon and tear gas. It was a freezing cold night and 17 people were treated in hospital, some for hypothermia.
|Protesters are urging boycotts of local, national and international businesses that support disputed projects [Reuters]|
Since then, the state government and local sheriffs department hasn't used such tactics, but nor have large groups of protesters approached the barricades as they did that night in November.
"We are all about prayer, non-violence, respect for the land and the water," says activist Dallas Goldtooth of the Indigenous Environmental Network. "We don't want trouble, we just want to protect the water and if we hadn't done this, that pipeline would be there just upstream from the Standing Rock community. A leak would be disastrous for everyone downstream."
The Sioux are a proud, enduring people whose territory once covered vast tracts of the Midwest. In the 19th century, they and other tribes signed treaties with the US government - some after protracted wars - but today many feel those agreements haven't been honoured by Washington.
They're also urging boycotts of local, national, and international businesses that support disputed projects on native land here and elsewhere.
Looming in the next few months though is a new administration led by President-elect Donald Trump, who has already supported the pipeline project and until recently held shares in the company that's building it.
If there's one hope that people cling to around the camp fires and at the barricades here, it's that the outgoing Obama administration blocks the project once and for all.