Police in riot gear began arresting the last remaining protesters at a makeshift camp in North Dakota on Thursday after they defied several orders to leave the area.

It’s unclear if any protesters remained at the camp after the police officers raided it.

The raids came after the eviction orders were unenforced for at least a day. Hundreds left peacefully on Wednesday after the 2 p.m. deadline, and 10 were arrested hours later after they taunted cops. But out of the tens of thousands that once called this prairie home, Gov. Doug Burgum said late Wednesday that 50 remained.

But hours later, 18 National Guardsmen and dozens of law officers entered the camp from two directions, along with several law enforcement and military vehicles. A helicopter and airplane flew overhead.

Officers checked structures and began arresting people, putting them in vans to take to jail. About two dozen people were arrested in the first half hour of the operation, according to Levi Bachmeier, a Burgum adviser.

North Dakota originally offered protesters a carrot. If they agreed to leave peacefully, they would receive a hotel room and bus ticket to anywhere in the U.S. As of Wednesday night, none had taken it. They also offered a courtesy or ‘ceremonial arrest’ for anyone needing a picture for their Facebook page. Again, no takers.

A 17-year-old girl and 7-year-boy old were burned after protesters set fire to the last remnants of the camp. They both required medical attention and one was air lifted to Minneapolis because her injuries were severe.

ARRESTS MADE IN NORTH DAKOTA, AS GROUP OF PIPELINE PROTESTERS REMAIN AT CAMP

Now the cleanup efforts begin. The camps span more than 1,000 acres, which had been, according to state officials, sensitive wildlife habitat. Now, because of an early thaw and thousands of “water protectors” it is a wet, muddy cesspool of human waste and hazardous fuels after protesters turned the native grassland into a dumping ground.

According to the Col John Henderson of the US Army Corp of Engineers, crews have already removed some 250 truckloads of trash, but his agency plans to spend upwards to $1.2 million of taxpayer money to rehabilitate the area.

"To ensure that none of this garbage and waste and debris and structures and vehicles ended up in the reservoir. That would be an absolute environmental catastrophe,” Henderson said.

Most of the protesters who spoke to Fox News said fighting the pipeline was a life-changing experience. They didn’t want the moment to end.

PIPELINE PROTESTERS SET FIRES AHEAD OF CAMP CLOSING

"I went home for a little bit but I came right back because I missed all of the people here. I missed the feeling.” said protestor Clarence Rowland, bundled up in a red sweater and purple hat as he walked around the few remaining tents in one of protestor camps.

Fellow protestor Genevieve Hock said she learned so much by being part of the demonstrations.

"We don't have to all have our own houses and cars…” Hock said. “We can work together and share resources and honestly live better and work less."

Includes reporting by The Associated Press.