"Nothing stands as a greater reminder to the Great Sioux Nation of a country that cannot keep a promise or treaty then the faces carved into our sacred land on what the United States calls Mount Rushmore," Harold Fraizer, chairman of the Cheyenne River Sioux Tribe said in a statement.
Critics have asked why Republicans have censored King while ignoring racist remarks from President Donald Trump.
The Trump budget abandons community policing and boosts military spending.
The protesters worry President-elect Donald Trump will reverse the government's decision after he takes office.
The Army Corps has insisted it has no plans to forcibly remove the anti-pipeline activists, many of them members of the Standing Rock Sioux Tribe.