...[The] Dakota Access oil pipeline...could carry more than 400,000 barrels of crude oil a day from the Bakken region of western North Dakota across South Dakota and Iowa to...Illinois... The 1,100-mile pipeline... is nearly halfway complete. But construction on a section that would sink beneath the Missouri River, just north of the reservation of the Standing Rock Sioux, has been halted under orders from the sheriff of Morton County, Kyle Kirchmeier...

[The] protesters say they are...[resisting] against what they say is a seemingly endless number of pipelines, export terminals and rail lines that would transport fossil fuels across or near tribal reservations, risking pollution to air, water and land.  “Every time there’s a project of this magnitude, so the nation can benefit, there’s a cost,” Dave Archambault, the chairman of the Standing Rock Sioux, who was among those arrested, said. “That cost is born by tribal nations.”...

Lawyers from Earthjustice are representing the Standing Rock Sioux in a legal effort to stop construction of the pipeline. They claim that the Army Corps of Engineers violated the National Historic Preservation Act when it approved the project and that a more stringent environmental review should be done. They say the pipeline and its construction would damage ancestral sites of the Standing Rock Sioux and put the tribe’s water supply at risk...

Energy Transfer Partners, the Texas company building it, says the pipeline will increase energy independence and that it’s safer than rail transport.