Thousands of veterans are making their way through snow and ice to form a human shield between protesters and law enforcement at North Dakota's Standing Rock.
The veterans will join demonstrators attempting to block the progression of the Dakota Access Pipeline, which would carry 470,000 barrels of crude oil each day underneath the Standing Rock Sioux Reservation. Representatives for the Standing Rock Sioux tribe say the pipeline will put sacred sites at risk and threatens to pollute the reservation's land and water supplies.
The group of veterans plan to take some of the pressure off protesters, who say police violence has "escalated" over the past week.
Veterans' activist group Veterans Stand for Standing Rock say those in attendance will be unarmed and the protest action will be non-violent.
"We don't even like the word 'protest.'" Ashleigh Jennifer Parker told USA Today. "We're here to help the water protectors.
Ms Parker said it was unconstitutional to have tax dollars paying to militarise police.
"People are being brutalized. Concussion grenades are being thrown into crowds," Parker said.
"They're spraying people, even old women, and other elders of the tribe with tear gas and pepper spray, and all of this is just unconstitutional."
Police have admitted using teargas grenades, sound weapons, Mace, pepper spray, Tasers and stinger, beanbag and sponge rounds against protesters. Activists say concussion grenades have also been used, and that the use of one led to the serious injury of Sophia Wilansky (22) last Sunday. Wilansky's father told The Guardian that the arteries, median nerve, muscle and bone in his daughter's left arm had been "blown away" and she could be looking at amputation of the limb. Police claim to have used no concussion grenades that day and say they are unsure as to how the injury was sustained.
Confusion spread throughout the camp after an emergency evacuation order was issued by authorities. Mid-week a Morton Country Sheriff spokesperson was quoted saying supplies would be blocked from reaching the camp. Officials later distanced themselves from the quote, but said people ordered not to return to the evacuation area would be subject to "penalties as defined in law."
Donations of more than $1.12M have been raised toward the veterans' "transportation, supplies, gear, onsite infrastructure and legal fees" through a crowd-funding campaign.
With more than 2100 veterans signed up to attend, capacity at the camp has been reached. Veterans Stand for Standing Rock is encouraging additional veterans who wish to volunteer to do so for "future missions", which "could be as early as the second week of December."
Volunteers have been asked to prepare for the possibility of arrest and have been told to bring body armor, gas masks, ear plugs and shooting mufflers.
Ms Parker says the first group of veterans will stay at the camp until December 7th, with some remaining at the site indefinitely.