A Washington state man accused of helping kill thousands of birds is expected to plead guilty Wednesday to shooting eagles on an American Indian reservation in Montana and selling their feathers and body parts on the black market.

The prosecution over golden and bald eagles killed on the Flathead Indian Reservation underscores the persistence of a thriving illegal trade in eagle feathers despite a law enforcement crackdown in the 2010s that netted dozens of criminal indictments across the U.S. West and Midwest.

A grand jury indictment last December quotes defendant Travis John Branson saying in a January 2021 text that he was going on a “killing spree” to obtain eagle tails. Branson and a second defendant, Simon Paul, killed approximately 3,600 birds, including eagles on the Flathead reservation and elsewhere, according to the indictment. Federal authorities have not disclosed how all the birds were killed, nor where else the killings happened.