Protests against the Dakota Access oil pipeline

JR American Horse, left, raises his fist with others while leading a march to the Dakota Access Pipeline site in southern Morton County North Dakota on Friday.

Native American protesters and their supporters are confronted by security personnel during a demonstration against work being done for the Dakota Access Pipeline, near Cannon Ball, N.D.

Native Americans march to a sacred burial ground site that was disturbed by bulldozers working on the Dakota Access Pipeline. Hundreds of people have gathered to join the Standing Rock Sioux tribe’s protest of the oil pipeline that is slated to cross the Missouri River near Cannon Ball, N.D.

Flags of Native American tribes from across the U.S. and Canada line the entrance to a protest encampment near Cannon Ball, N.D., where members of the Standing Rock Sioux tribe and their supporters have gathered to voice their opposition to the Dakota Access Pipeline.

Native American protesters wave a clan flag over land designated for the Dakota Access Pipeline after confronting contractors and private security guards working on the oil pipeline project.

Two children walk together in an oil pipeline protest encampment near Cannon Ball, N.D., where members of a Native American tribe and their supporters have gathered to voice their opposition to the Dakota Access Pipeline.

Protesters against the construction of the Dakota Access oil pipeline on the Standing Rock Reservation in North Dakota head to a unity rally on the west steps of the State Capitol in Denver. Several hundred marchers walked from the four directions of the compass to the Capitol to take part in the rally against the oil pipeline.

Native American protesters and their supporters demonstrate against work being done for the Dakota Access oil pipeline near Cannon Ball, N.D.

Members of the Standing Rock Sioux tribe and their supporters confront bulldozers working on the Dakota Access Pipeline near Cannon Ball, N.D.  (Robyn Beck / AFP/Getty Images)

Tents and a flag are seen at an oil pipeline protest encampment near Cannon Ball, N.D.

A Native American protester pauses on land being prepared for the Dakota Access Pipeline after confronting employees and private security guards working on the oil pipeline project.