Police pursued an armed gunman - believed to be an Iraq war vet - through Mount Rainier National Park's snowy terrain Monday after a park ranger was shot to death, while other officers used the cover of morning darkness to evacuate more than 100 tourists from a guarded visitors center.
About 150 officers converged on the mountain park after ranger Margaret Anderson was shot to death Sunday morning, and searchers used an aircraft with heat-sensing capabilities to hunt from the skies.
Authorities believe the gunman is still in the woods, with weapons.
Pierce County Sheriff's spokesman Ed Troyer said that Benjamin Colton Barnes, a 24-year-old Iraq War veteran believed to have survivalist skills, was a "strong person of interest" in the slaying.
"We do have a very hot and dangerous situation," Troyer said.
It has been legal for people to take loaded firearms into Mount Rainier since 2010, when a federal law went into effect that made possession of firearms in national parks subject to state gun laws.
Safety concerns prompted authorities to keep about 125 tourists quarantined at a visitors center as the manhunt unfolded.
But early Monday morning, officers escorted them in their cars out of the park. Troyer said it was determined to be "better to do it (evacuate) under the cover of darkness than daylight."
Evacuee Dinh Jackson, a mother from Olympia, Washington, who came to the mountain to sled with family and friends, told The Associated Press that officials ordered people to hurry into the lodge after the shooting.
Jackson said officials had everyone get on their knees and place hands behind their heads as they went through the building, looking at faces to make sure the gunman was not among them.
"That was scary for the kids," she said.
A parks spokesman said Barnes was an Iraq war veteran, and the mother of his child had alleged he suffered from post-traumatic stress following his deployments.
Barnes was involved in a custody dispute in Tacoma in July 2011, during which the toddler's mother sought a temporary restraining order against him, according to court documents. In an affidavit, the woman wrote that Barnes was suicidal and possibly suffered from PTSD after deploying to Iraq in 2007-2008. She said he gets easily irritated, angry and depressed and keeps an arsenal of weapons in his home.
Barnes was also a suspect in an early Sunday morning shooting that that left four people injured, two critically, at a house party south of Seattle, police said.
At Mount Rainier around 10:20 a.m. Sunday, Bacher said the gunman had sped past a checkpoint to make sure vehicles have tire chains, which are sometimes necessary in snowy conditions. One ranger began following him while Anderson, a 34-year-old mother of two young children who was married to another Mount Rainier park ranger, eventually blocked the road to stop the driver.
Before fleeing, the gunman fired shots at both Anderson and the ranger that trailed him, but only Anderson was hit, Bacher said. Anderson would have been armed, as she was one of the rangers tasked with law enforcement, Bacher said. Troyer said she was shot before she had even left the vehicle.
Tactical responders wearing crampons and snowshoes pursued what appeared to be the gunman's tracks in the snow, Troyer said. Those tracks went into creeks and other waterways, making it more difficult for crews to follow.
"He's intentionally trying to get out of the snow," Troyer said.
Authorities recovered his vehicle, which had weapons and body armor inside, Troyer said.
The park would remain closed Monday, officials announced late Sunday.
Associated Press writer Donna Gordon Blankinship contributed from Seattle.