UPDATED at 1:40 p.m. with additional information from the newly unsealed indictment.

UPDATED at 12:43 p.m. to include information about Cooper's jail booking and the charge against him, as well as his wife's posts on Facebook.

UPDATED at 9:28 a.m. to include more information about Cooper's whereabouts since leaving the refuge as well as the arrests of others involved in the occupation.

Blaine Cooper, a member of the core group that took over the Malheur National Wildlife Refuge on Jan. 2, was arrested Thursday in southwestern Utah.

He was booked into jail in Washington County, Utah, which includes the city of St. George, online jail records show. The arresting agency was listed as the FBI.

An indictment was unsealed in federal court in Portland on Thursday. Cooper was charged with conspiracy to impede officers of the United States, the same charge that has been leveled against at least 20 others involved in the 41-day bird sanctuary occupation.

Blaine Cooper

Cooper's wife, Melissa Cooper, took to Facebook following the arrest to solicit donations and update supporters. She also participated in the occupation, helping to organize supplies and cook.

Melissa Cooper wrote on Facebook that she was taking her two daughters back to Arizona. Officers arrested her husband in front of her and the children at the Canyon Ranch Motel in Springdale, Utah, she said. The family lives in Dewey-Humboldt, Arizona, a suburb of Prescott.

Blaine Cooper, 36, attended the memorial for occupation spokesman Robert "LaVoy" Finicum on Friday in Kanab, Utah. Asked why he had not been included in the first indictment linked to the occupation, Cooper said, "Luck maybe."

He said Friday that he had not been home since he left the refuge Jan. 26 after learning that Finicum had been killed at a law-enforcement roadblock. He traveled in an armed convoy to Nevada and had been in Utah in preparation for Finicum's memorial.

Among the the others in the most recent round of arrests was Cliven Bundy, the Nevada rancher who touched off an armed showdown with federal authorities in 2014 and applauded the occupation in Oregon that was organized by two of his sons.

Bundy was arrested late Wednesday at Portland International Airport and faces federal charges related to the 2014 standoff at his ranch. He also attended Finicum's memorial in Utah last week.

Six others have been named in the indictment that named Cooper. They are Corey Lequieu, 45, of Nevada; Neil Wampler, 68, of California; Jason Charles Blomgren, also known as "Joker J"; Darryl William Thorn, Wesley Kjar; and Eric Lee Flores. Two names remained redacted Thursday afternoon.

Wampler was convicted in 1977 of second-degree murder in the killing of his father.

This post will be updated when more information is available.

-- The Oregonian's Everton Bailey Jr. contributed to this report.

-- Carli Brosseau

cbrosseau@oregonian.com

503-294-5121; @carlibrosseau