The Standing Rock Sioux Tribe was notified on Friday by the U.S. Army Corps of Engineers that the North Dakota encampment area must be vacated by December 5 for safety concerns.
The area has been occupied for months by protesters opposing the four-state, $3.8 billion Dakota Access pipeline under construction by Dallas-based Energy Transfer Partners.
John W. Henderson, a district commander with the Corps, sent a letter to Standing Rock Sioux tribal leader Dave Archambault II placing the public on official notice that anyone found on “Corps-managed land” north of the Cannonball River after the early December deadline will be prosecuted for trespassing.
“This decision is necessary to protect the general public from the violent confrontations between protesters and law enforcement officials that have occurred in this area, and to prevent death, illness, or serious injury to inhabitants of encampments due to the harsh North Dakota winter conditions,” said Henderson, in the letter.
The Corps previously said it would not evict protesters on the basis of free speech.
Despite the eviction notice, protest organizers vow to remain on the property and continue their acts of civil disobedience.
Since August, over 525 protesters have been arrested at the site. Several injuries from recent confrontations have been reported by the media.
Nearly $20 million in additional law enforcement costs have been incurred as a result of the protest, according to North Dakota officials.