A massive manhunt was under way early Monday for a man wanted for questioning in the shooting death of a park ranger and a shooting that left four injured in Washington state.
Federal and local authorities described Benjamin Colton Barnes, 24, as a "person of interest" in the shooting of park ranger Margaret Anderson at Mount Rainier National Park on New Year's Day.
He is believed to be heavily armed and wearing body armor, according to authorities who scoured the rough park terrain looking for him.
"This is probably somebody who is experienced with the outdoors," Pierce County Sheriff Ed Troyer told CNN affiliates KOMO and KIRO of Seattle.
Barnes is also wanted in connection with a shooting Sunday in the Seattle suburb of Skyway that left four people wounded, the affiliates reported, citing the King County Sheriff's Department.
The park shooting began with "a normal traffic stop" around 10:30 a.m. PT (1:30 p.m. ET), Mount Rainier National Park spokeswoman Lee Taylor told CNN. But the suspect didn't heed a request to pull over, prompting a ranger to radio ahead requesting assistance.
Anderson, 34, responded to that call and set up her patrol vehicle as a roadblock. When the gunman arrived at the roadblock, he got out of his car and shot her, Taylor said.
Anderson managed to call for help, alerting Pierce County Sheriff's deputies that she had been shot, Troyer said.
Deputies "tried to get to her, and they were fired upon," Troyer said. "They managed to get a small team together to get to her, and get her out of the line of fire. Medic checked her and, unfortunately, she was dead."
The suspect then ran into the spacious national park, whose border is about 50 miles southeast of Seattle, authorities said. The park -- the centerpiece being the 14,410-foot Mount Rainier, which is considered an active volcano -- comprises 235,625 acres in the Cascade Range.
Investigators found evidence of weapons and body armor in the suspect's car, Troyer said.
Authorities are using helicopters equipped with infrared cameras and an airplane armed with flares to track the gunman in the park overnight, said Sgt. Tom Martin of the Washington State Patrol. More than 150 local, state and federal law enforcement officers are involved in the search, authorities said.
The park was locked down after the shooting. Taylor said authorities evacuated "most of the people ... safely," with more than 100 people "holed up in our primary visitor center" with food, water and five law enforcement officers standing guard.
More than 12 hours after the lock down began, state troopers began escorting dozens of tourists off the mountain, Martin told CNN. By early Monday morning, troopers were still working to get everybody out of the visitors center, he said.
Between 4 to 5 feet of snow is on the ground.
"There's a lot of snow on the ground, (and) it would be difficult to move through quickly," Taylor said. "And it's heavily forested."
Anderson was the mother of a 4-year-old and 1-year-old, and the wife of a fellow park ranger, according to Taylor.
A ranger at Mount Rainier for the past four years, Anderson "was on the job not for money or for glory, but out of a love for wild places and the national parks," Taylor said.
"She was a person with a quick smile, a very gentle person, a very competent ranger," Taylor said. "This gunman took the life of somebody who had a great deal to live for and was making great contributions to society by being a national park ranger."