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.

Branson, of Cusick, Washington, sold an unidentified purchaser two sets of golden eagle tail feathers – highly prized among many Native American tribes – for $650 in March 2021, according to court documents.

Less than two weeks later, law enforcement stopped Branson on the reservation and found in his vehicle the feet and feathers of a golden eagle he had shot near Polson, Montana, according to filings that included a photo of the bird’s severed feet with their massive talons. The bird’s carcass had been “cleaned” by the second defendant, Simon Paul, and was found in a nearby field, prosecutors wrote.

Multiple phones seized by authorities during the stop yielded photos and text messages that described “the shooting, killing and ultimate selling of bald and golden eagles throughout the United States,” prosecutors said.

Feathers and other parts of eagles are illegal to sell but widely used by Native Americans in ceremonies and during powwows.

Branson, who remained free following the indictment, reached a deal with prosecutors last month to plead guilty to four counts: conspiracy, wildlife trafficking and two counts of trafficking in federally protected bald and golden eagles.

Branson could not be reached for comment before Wednesday’s hearing in Missoula. His public defender declined comment while the case is pending.

Paul of St. Ignatius, Montana, remains at large. A federal judge issued an arrest warrant for Paul when he did not show up for an initial court hearing in December.

The indictment described Branson and Paul trafficking golden and bald eagles or their parts on at least 11 occasions between December 2020 and the stop of Branson by law enforcement on March 13, 2021.

But court filings suggest the illegal activity went on much longer. They outline a conspiracy that began in 2015 and involved other people who killed eagles on the Flathead Reservation but have not been publicly identified.

In a 2016 text message quoted by prosecutors, Branson appeared to acknowledge that shipping eagles internationally was illegal, adding, “I just get em for 99 cents…price of a bullet.”

In another text exchange, Branson was negotiating an eagle feather sale when he allegedly wrote, “I don’t get em for free though….out hear (sic) committing felonies,” according to the court filings.

The indictment also alleges that on March 13, 2021, Branson and Paul returned to a previously killed deer to lure eagles and that Branson shot a golden eagle. Paul cleaned the golden eagle and both men placed various golden eagle parts in a vehicle for transport, prosecutors said.

Branson faces up to five years in prison and a $250,000 at sentencing on most serious charge, conspiracy. Under the plea deal, lawyers for the U.S. Attorney’s Office in Montana said they would seek to dismiss additional trafficking charges and would recommend a sentencing guideline reduction that could lessen the severity of Branson’s punishment.

The criminal case comes almost a decade after a multi-state U.S. Fish and Wildlife Service trafficking investigation dubbed “Operation Dakota Flyer” led to charges against 35 defendants and the recovery of more than 150 eagles, 100 hawks and owls and 20 species of other protected birds that were seized or bought by authorities in undercover purchases, according to federal officials.

Federally recognized tribes can apply for permits with the U.S. Fish and Wildlife Service to take a bald or golden eagle for religious purposes, and enrolled tribal members can apply for feathers and other bird parts from the National Eagle Repository in Colorado and non-government repositories in Oklahoma and Phoenix. There’s a yearslong backlog of requests at the National Repository and researchers say the high demand is fueling the black market for eagle parts.

The Bald and Golden Eagle Protection Act was enacted in 1940 to protect the bald eagle. In 1962, Congress extended the Act to protect golden eagles.

Bald eagles were decimated by habitat destruction and degradation in the mid 1900s and in danger of going exctinct, but in recent decades, habitat protection and conservation actions have “helped bald eagles make a remarkable recovery,” the Fish and Wildlife Service says. There are more than 316,000 bald eagles in the lower 48 states, based on data from 2018 to 2019.

They can live up to about 30 years in the wild.