Dakota Access pipeline protest site cleared after police in riot gear enter main camp

— -- The protest site for the Dakota Access pipeline has been cleared after some demonstrators refused to leave Wednesday, when a deadline for evacuation passed.

The Oceti Sakowin camp was cleared as of 2:09 p.m. local time, a spokesperson for the North Dakota Joint Information Center told ABC News.

About 50 demonstrators who remained in the camp were present when law enforcement made announcements to disperse or be arrested, according to the North Dakota JIC. About two dozen people who did not comply were arrested.

While many protesters exited the camp voluntarily throughout the day, law enforcement arrested about 46 people total Thursday as the process to clear the camp progressed.

One veterans group occupying a tent refused to leave voluntarily, the North Dakota JIC said. The group informed law enforcement that they would not be violent but would only go with passive resistance, so they were carried out of the camp by authorities.

“I am very happy to say that we finally introduced rule of law in the Oceti camp,” said Morton County Sheriff Kyle Kirchmeier. “I am hopeful that this announcement brings us closer to finality in what has been an incredibly challenging time for our citizens and law enforcement professionals. Having dealt with riots, violence, trespassing and property crimes, the people of Morton County are looking forward to getting back to their normal lives.”

This morning, more than 200 law enforcement officers clad in full riot gear entered the main encampment for those protesting the Dakota Access pipeline near Cannon Ball, North Dakota, where some people remained despite state and federal orders to leave.

ABC News observed lines of military-style Humvees entering the camp, which is at the edge of the Standing Rock Sioux Tribe reservation.

Officials said most people left the soggy campsite peacefully on Wednesday before the 2 p.m. deadline, amid concerns about spring flooding. But as many as 50 people remained there Wednesday night, and authorities were still deciding this morning how to remove them.

Activists protesting the four-state Dakota Access crude oil pipeline told ABC News on Wednesday that they are committed to staying and estimated that dozens would remain in the Oceti Sakowin camp.

On Wednesday, 11 people were arrested outside the camp at its main entrance, outside a barrier put up protesters to keep out authorities. Those who were arrested were charged with obstruction of a government function, a class B misdemeanor, Gov. Doug Burgum said at a news conference that night.

The protesters lit about 20 fires on Wednesday, which were characterized as ceremonial, with many saying they would rather burn camp structures than have authorities seize and destroy them. Two people in the camp were injured as a result of the fires, including one person with severe burns who had to be airlifted to Minneapolis for treatment.

Burgum set up a travel assistance center to offer camp residents water, snacks, a food voucher, a personal hygiene kit, a health and wellness assessment, hotel lodging for one night, a taxi voucher to local bus terminal and bus fare for a return trip home, and transportation was provided from the Oceti Sakowin camp to the assistance center in Bismarck.

"This free service will provide protesters with support as they prepare for their return home," Burgum's office said in a Facebook post on Tuesday night. "All camp residents are encouraged to take advantage of these amenities."

Last week Burgum signed an emergency evacuation order for the camp that reaffirmed a Feb. 22 deadline set by the U.S. Army Corps of Engineers. The Standing Rock Sioux Tribe began coordinating a cleanup in late January, but state officials said it wasn't happening fast enough. The governor's emergency evacuation order cited increasing temperatures and the threat of flooding as the impetus for accelerating the camp's cleanup.

"Warm temperatures have accelerated snowmelt in the area of the Oceti Sakowin protest camp, and the National Weather Service reports that the Cannonball River should be on the watch for rising water levels and an increased risk of ice jams later this week," the statement from Burgum's office read.

"Due to these conditions, the governor's emergency order addresses safety concerns to human life, as anyone in the floodplain is at risk for possible injury or death. The order also addresses the need to protect the Missouri River from the waste that will flow into the Cannonball River and Lake Oahe if the camp is not cleared and the cleanup expedited," the statement added.

The Cannonball River is a tributary of the Missouri River.

The 1,172-mile Dakota Access pipeline is nearly finished, except for a 1.25-mile segment, part of which will run under Lake Oahe, a Missouri River reservoir in just upstream of the Standing Rock Sioux Tribe reservation. Construction of this final phase has been the focus of a contentious legal battle and massive protests in recent months.

While the Army Corps says this area is federally owned land, the Standing Rock Sioux Tribe cites an 1851 treaty that it says designates the land for Native American tribes. The tribe, which claims its members were never meaningfully consulted before construction began, sued in July to block the pipeline. That lawsuit is pending, and the Army Corps and the company behind the pipeline argued in court papers that they followed a standard review process.

The Standing Rock Sioux Tribe has been at the forefront of the fight against the $3.8 billion Dakota Access pipeline. The protests have drawn thousands of Native Americans, environmental activists and their allies to the Standing Rock Sioux Tribe reservation. The protesters, who call themselves water protectors, argue that the pipeline will threaten the reservation's water supply and traverse sacred sites.

Kelcy Warren, the CEO of Energy Transfer Partners, the Texas-based developer behind the project, has said that "concerns about the pipeline's impact on local water supply are unfounded" and "multiple archaeological studies conducted with state historic preservation offices found no sacred items along the route."

ABC News' David Caplan, Joshua Hoyos, Tom Kutsch, Luis Martinez, Bartley Price, Darren Reynolds, Evan Simon and Catherine Thorbecke contributed to this report.