David Fry, 27, stayed behind for more than an hour and told supporters by phone he had not agreed with the other three to leave the Malheur National Wildlife Refuge in eastern Oregon. The call was broadcast live on an audio feed posted on the Internet.

"I'm actually pointing a gun at my head. I'm tired of living," Fry said during the phone call. He later added: "Until you address my grievances, you're probably going to have to watch me be killed, or kill myself."

Fry sounded alternately defiant and tormented during the rambling final call, veering from rants about the federal government to his thoughts on UFOs. He surrendered after taking a final cigarette and cookie and asking his mediators to shout "Hallelujah."

Authorities could be heard over the phone line telling him to put his hands up before the call disconnected. Harney County Sheriff Dave Ward called him a "very troubled young man" at a news conference several hours later.

Federal authorities said the refuge would remain closed for several weeks as agents secured what was now considered a crime scene and scoured it for fugitives or explosives.

The protesters told authorities they left behind booby traps but did not say whether the trip wires and other devices would trigger explosions, a law enforcement official told Reuters.

Materials to create explosives could be found on the property, said the official, speaking on the condition of anonymity.

The final four occupiers will face charges of conspiracy to impede federal officers, along with 12 others previously arrested, officials said.

"The occupation of the Malheur Wildlife Refuge has been a long and traumatic episode for the citizens of Harney County and the members of the Burns Paiute tribe," U.S. Attorney Billy Williams said in the statement. "It is a time for healing, reconciliation amongst neighbors and friends, and allowing for life to get back to normal."

CLIVEN BUNDY ARRESTED

The takeover, which began on Jan. 2, was sparked by the return to prison of two Oregon ranchers convicted of setting fires that spread to federal property in the vicinity of the refuge.

The standoff, which was originally led by brothers Ammon and Ryan Bundy, came to a head after the arrest on Wednesday in Portland of their father, Cliven Bundy. On Thursday, he was charged with conspiracy, assault on a federal officer and obstruction of justice in connection with a separate 2014 standoff on federal land near his Nevada ranch.

Cliven Bundy was subdued during a brief court appearance in Portland, appearing pale and tired in a jail uniform and eyeglasses. He spoke only to acknowledge his rights to the judge.

The Malheur occupation had also been a protest against federal control over millions of acres (hectares) of public land in the West.

Ammon and Ryan Bundy were arrested in January along with nine other protesters on a snow-covered roadside where a spokesman for the group, Robert "LaVoy" Finicum, was shot dead. A 12th member of the group surrendered to police in Arizona.

After Cliven Bundy's arrest, three of four remaining occupiers surrendered to the FBI at the urging of Nevada state Assemblywoman Michele Fiore and the Rev. Franklin Graham, the son of Christian evangelist Billy Graham.

Jeff Banta, 46, of Elko, Nevada, and married couple Sean Anderson, 48, and Sandy Anderson, 47, of Riggins, Idaho, surrendered peacefully, according to the FBI.

Fiore told Reuters in an interview that she and Graham hugged each of the holdouts as they emerged and that they seemed relieved.

“No one got scratched, no one got thrown on the ground and nothing happened,” Fiore said.

Fry arrived at the occupation within the first week, and told Oregon Public Broadcasting that he was inspired by Finicum. He became one the most outspoken protesters, posting frequent, often angry rants on social media.

The skinny, bespectacled Ohio native from a military family has also expressed outrage when dealing with what appear to be minor criminal offenses in his past. In a YouTube video from September, Fry can be heard saying he refused to pay fines “for smoking marijuana on a river and not wearing a life jacket,” and then sets fire to a debt collection notice.

Fry’s father told Oregon Public Broadcasting his son had also screamed at a police officer who had pulled him over for broken taillights. The elder Fry said his son was bullied in high school because of his Japanese heritage.

(Additional reporting by Shelby Sebens in Portland, Oregon; Barbara Goldberg and Joseph Ax in New York, Julia Edwards in Washington, Eric M. Johnson in Seattle and Dan Whitcomb in Los Angeles; Writing by Alex Dobuzinskis and Dan Whitcomb; Editing by Sara Catania, Jeffrey Benkoe, Lisa Shumaker and Peter Cooney)