FBI agents found evidence at the Malheur National Wildlife Refuge that occupiers used a boat launch area for firearms training, discovering about 1,685 spent shell casings there, according to a new federal complaint.

The government is seeking the civil forfeiture of 50 guns and huge caches of ammunition that federal agents either seized from the refuge after the 41-day occupation or from defendants' cars and homes, the complaint says. Authorities earlier seized 14 other guns in or near the refuge in January.

Defendant Ammon Bundy and supporters took control of the refuge on Jan. 2. The occupation led to the indictment of Bundy and 25 other people on charges of conspiring to impede federal workers from doing their jobs at the federal bird sanctuary in eastern Oregon's Harney County.

The government must file for forfeiture of evidence within 120 days of its seizure. Notices will go out to owners of the weapons, who have the right to challenge the forfeitures.

FBI agents searched the refuge grounds and buildings after the last four people surrendered, from Feb. 12 through Feb. 23, the complaint says.

They found most of the guns at the outside encampment on the refuge's west side where the holdouts of the occupation camped during the final two weeks, according to the complaint: at least six rifles, two handguns and boxes of shotgun shells and assorted ammunition there. They also found shotgun shells in one of three trenches that occupiers dug at the site, FBI special agent Katherine Armstrong wrote in the complaint.

Agents also recovered boxes of ammunition from the refuge's firefighter bunkhouse and in two offices in refuge buildings. Among the seized ammunition were hollow point bullets, Armstrong noted.

The occupiers carried the weapons as a "show of force and intimidation,'' she said, partly to ensure "that the demands they made would be taken seriously,'' to defend themselves if law enforcement engaged them and to conduct regular security patrols.

Defendant Ryan Payne and others helped split the occupiers into teams to cover guard shifts, patrolling the blocked refuge entrances and manning the refuge watchtower, Armstrong wrote.

"When not on duty, some teams would practice patrol movements,'' Armstrong wrote. "There was firearm training at the refuge as well, though not all occupiers participated.''

The more than 1,600 shell casings that FBI agents found at the refuge were seized from the refuge's boat launch area, located about 1.5 miles northeast of the refuge RV parking area, the complaint says.

Defendant Jason Blomgren, after his arrest in Nevada, told agents that he began carrying a .40-caliber pistol at all times after the Jan. 26 fatal shooting of occupation spokesman Robert "LaVoy" Finicum by state police outside the refuge. He was concerned officers would try to kill him and wanted to protect himself. Blomgren told agents he received the gun from another occupier who wasn't indicted.

Co-defendant Eric Flores, who pleaded guilty to a federal conspiracy charge this week, told authorities he brought all his guns to the refuge and handed them out to others. Prosecutors said he carried seven guns to the refuge. He said he left six weapons at the refuge, which he agreed to forfeit as part of a plea agreement he signed.

Flores told the FBI he gave fellow Washington resident and co-defendant Darryl Thorn an AR-15 rifle and a CZ Rami .40-caliber pistol. When Thorn was arrested on Feb. 11 at a Super 8 Motel in Redmond, agents seized the pistol from his hotel room, Armstrong wrote.

Scott Willingham, who wasn't charged in the federal conspiracy but indicted separately for theft of government property, told authorities he took a rifle from Payne's truck before leaving the refuge. He said the .308-caliber rifle was one Payne had when he served in Afghanistan, the complaint says. Willingham was part of the security team during the refuge and last month pleaded guilty to taking or converting government-owned cameras for his own use.

The FBI alleges that the guns were used in the alleged conspiracy to intimidate and impede 16 federal employees from working at the refuge, including a federal law enforcement officer and a volunteer coordinator who worked in the visitor center and lived on the refuge. During the occupation, the U.S. Bureau of Land Management closed its Burns district office, where about 80 people work, out of concern for their safety. They weren't allowed to return to work until Feb. 29, the complaint says.

-- Maxine Bernstein

mbernstein@oregonian.com

503-221-8212

@maxoregonian