Authorities on Friday surrounded a deep woods bunker they say belongs to a gun-toting survivalist suspected of killing his wife and daughter nearly a week ago.

They pumped gas into the structure in the Cascade foothills east of Seattle and saw movement inside, but the dozens of officers were not going into the bunker because they worried it could be booby-trapped.

"It's a very extreme tactical situation," King County Sheriff Steve Strachan said. "Time is on our side. We're not going to do anything rash."

Authorities said the bunker belongs to 41-year-old Peter A. Keller, who has not been seen since a Sunday fire at his North Bend-area home led responders to discover the bodies of his wife and daughter. The two had been shot to death.

Authorities were waiting to see if the person in the bunker would surrender.

King County Sheriff's Sgt. Cindi West said evidence found in Keller's home helped them find the elaborate structure Friday morning.

Officers were able to pinpoint the location after enhancing a blurry photograph found on a hard drive in an open safe in Keller's house. The photo included a view from the bunker in which buildings in nearby North Bend were visible, along with a set of power lines.

Detectives triangulated the rough area of the bunker and were confidant they had the right location after receiving tips from people who had seen Keller's faded red pickup truck parked at the trailhead, West said.

Two experienced trackers were sent to the trailhead and found tracks that appeared to have been made by someone carrying a heavy backpack.

They went into the woods at 5 a.m. and could smell wood smoke from the wood stove in the bunker, even before they could see it, West said.

The bunker was at about the 1,350-foot level, several hundred yards due east of a trailhead at Rattlesnake Ridge in a heavily overgrown area. It was dug about 20 feet into the side of a hill, and had several entryways and ladders.

"This isn't a hole in the ground. It's an elaborate structure," Strachan said.

Court documents described Keller as a loner who collects guns, has a survivalist mentality and has been stockpiling supplies in the woods.

An arrest warrant issued Wednesday accuses him of two counts of first-degree murder and one count of first-degree arson.

The fire at Keller's home was stopped before the house burned down, and authorities said they found seven gasoline cans placed in different areas of the home.

The King County medical examiner has determined Kaylene Keller, 18, and her mother, Lynnettee Keller, 41, both died from gunshots to the head. Their bodies were found in their bedrooms.

Kaylene's boyfriend told detectives that Peter Keller had shown him his gun collection and several large-caliber rifles and handguns, court documents said. The boyfriend, who was not identified, said Kaylene had told him her father took long hikes on the weekends and was stockpiling supplies at a fort in the woods.

Peter Keller withdrew $6,200 from a bank last week and told one of his co-workers at a computer refurbishing store in Preston that he might not return, according to court documents.

Officers with the SWAT team had spent Friday morning searching a popular hiking area known as Rattlesnake Ridge just outside North Bend. Deputies closed trails and roads leading into the area of dense trees and networks of hiking and biking trails. Sheriff's vehicles dotted housing developments that abutted the ridge.

Sally Betts of Vashon Island had been hoping to hike Rattlesnake Ridge with her friends from the Renton Women's Hiking Club, but drove off for another trail after learning of the search.

"We thought that Rattlesnake is so popular, he wouldn't be there. He's an outdoorsman _ he'll be off on the wilderness somewhere," Betts said.