Twenty-eight members of the Nez Perce tribe, including eight members of the tribe's executive committee, are charged with public nuisance infractions for protests last month seeking to stop a "megaload" from traveling through the reservation.
The Lewiston Tribune reports the charges were filed Wednesday.
Tribal executive committee chairman Silas Whitman was among those charged. Court documents say those charged entered the eastbound lanes of U.S. Highway 12 early on Aug. 6 "while traffic was attempting to proceed and refused to leave the highway."
An arraignment is set for Sept. 20 in Nez Perce Tribal Court. Special Prosecutor Michael Cherasia was appointed to handle the cases.
The equipment they tried to stop is to be used to treat water at an oil sands project in Alberta, Canada.