Members of American Indian tribes are bringing their frustrations with the Trump administration and its approval of the Dakota Access oil pipeline to the nation’s capital.

Tribal members were planning to gather at the National Mall today to begin four days of activities culminating with a Friday march on the White House dubbed the “Native Nations March on D.C.”

Tribal members and supporters plan to camp each day on the National Mall, with teepees, a ceremonial fire, cultural workshops and speakers. Native American leaders also plan to lobby lawmakers to protect tribal rights.

On Friday, a march of about 2 miles is planned from the Army Corps of Engineers office to the White House, where a rally is scheduled. Organizers didn’t immediately have an estimate on how many people or tribes planned to take part.

“We are calling on all our Native relatives and allies to rise with us,” said Dave Archambault, the chairman of the Standing Rock Sioux tribe. “We must march against injustice. Native nations cannot continue to be pushed aside to benefit corporate interests and government whim.”

The White House didn’t immediately respond to a request for comment.

The protest comes as a federal judge in Washington is weighing a request by the Standing Rock and Cheyenne River Sioux tribes to halt construction of the last section of the Dakota Access pipeline pending the outcomes of their lawsuit seeking to stop the project.

The tribes say that section of the pipeline, which will pass under Lake Oahe, a large Missouri River reservoir, will threaten their water supply, sacred sites and religious rights. The judge is expected to rule this week.