Today marked the deadline established by North Dakota’s governor for Dakota Access pipeline protestors to leave the Oceti Sakowin camp.

This morning, about 100 people remained on site, with some torching structures within the camp they called “ceremonial fires.” But most of those protestors opted to leave this afternoon, playing drums and singing on their final walk away from the camp.

Around 5 p.m. EST, police made nine arrests at a roadway near the camp, a Bismarck police officer told Heat Street. Earlier in the day, law enforcement stood in place near Oceti Sakowin, awaiting direction from Gov. Doug Burgum.

Before those arrests, a spokesman for Gov. Doug Burgum spoke near the camp late Wednesday afternoon, saying anyone who remained was trespassing and may be detained.

Media contacts for the Morton County sheriff’s department could not be reached by deadline. On its Facebook page, the sheriff’s department said it had received a report that two people were taken by ambulance to the hospital after sustaining burns when protestors set fire to camp structures.

Protestors who voluntarily left the Oceti Sakowin camp were guided to “amnesty buses” and taken to a local family center.

The North Dakota Department of Human Services, Department of Emergency Services, and Department of Health are working together to provide the protestors with health screenings and food, also offering bus tickets, gas cards or other assistance to send protestors home.

The governor’s spokesman said Wednesday afternoon that the Army Corps planned to clean up the site at 9 a.m. Thursday. Earlier this month, North Dakota officials expressed concerns that the trash left behind by Standing Rock protestors could cause an environmental disaster.

North Dakota saw record snowfall this winter, and the state is concerned about contaminated floodwaters reaching the Missouri River. The Standing Rock Sioux Tribe has been leading a cleanup effort, working alongside local and state authorities.

At its peak, the Standing Rock protests drew as many as 10,000 demonstrators from across the United States. Since August, the state has spent at least $8.7 million policing the protests, the North Dakota National Guard said.

In 2016, authorities arrested at least 565 people in connection with the pipeline protests, though some later saw their charges dropped. Nine out of 10 demonstrators charged with a crime in 2016 came from out of state, a sheriff’s department spokeswoman said in December. On Feb. 1, law enforcement arrested an additional 76 people who had tried to erect a new campsite on private lands.

Authorities said the protestors had resorted to violence, also harassing law enforcement and their families. Farmers and local businesses also said some protestors had menaced them.

At the Obama administration’s behest the U.S. Army Corps of Engineers denied a easement necessary for the pipeline’s construction. In January, Donald Trump signed an executive order pushing the Army Corps to review that decision. In February, the Army Corps approved that critical easement, allowing the pipeline to proceed.

— Jillian Kay Melchior writes for Heat Street and is a fellow for the Steamboat Institute and the Independent Women’s Forum.