The Pinnacle Lake Trail where the women were found and the U.S. Forest Service road leading to it were open on Thursday, but closed Friday for further investigation, Deputy Rich Niebusch told a news conference.
Investigators were trying to determine who was responsible for the killings. Niebusch said a random attack had not been ruled out, and he urged anyone hiking on nearby trails to be extra cautious.
The Snohomish County medical examiner's office identified the victims as Mary Cooper, 56, and her daughter, Susanna Stodden, 27, both of Seattle, but at the sheriff's office request, released no information about how they died other than to say they were victims of homicide.
The women were last seen alive around 10 a.m. Tuesday. A passer-by found their bodies a few hours later toward the end of a nearly 2-mile trail to Pinnacle Lake, about 50 miles northeast of Seattle and south of Verlot in the Mount Baker-Snoqualmie National Forest, Niebusch said.
Chuck Keller, 74, manages the nearby Gold Basin campground, where the passer-by reported his discovery to authorities. Keller said the man and a woman he'd been hiking with were visibly shaken.
"He said he saw two ladies on the trail that looked like they were going to the bathroom, then he looked at them and saw they were deceased and they left in a hurry," Keller said.
Diane Boyd, who works the front desk at the Verlot ranger station, said it's been unsettling to know so little about how the women died. "It's terrible no matter what, but if it turns out to be random, it's going to be much more destroying to this area," Boyd said.
On Wednesday, investigators worked at the scene and carried the bodies to the nearest road by foot. The trail was open on Thursday, but appeared deserted. The only vehicles parked near the trailhead belonged to TV news crews.
Most avid hikers relish the chance to have a trail all to themselves, but when Greg Gross found out about the killings, he decided he would rather have company.
"I decided I was not going to go any place that didn't have any cars in the parking lot," the 60-year-old emergency room doctor said Thursday after finishing a solo hike up to Lake Twentytwo, not far from Pinnacle Lake.
Barbara Troyer, a retiree from Lynnwood, hiked to Lake Twentytwo with a group of friends Thursday, opting not to cancel a trip that had been planned for weeks.
"I was skittish about it in case it was a sniper-type thing," said one of her hiking companions, Gary Hirst, 62 of Edmonds. "I just left it up to the women - said if you feel uncomfortable we won't go."
The FBI was aiding the investigation because the killings took place in a national forest, but the sheriff's office remained in charge of the probe, said Robbie Burroughs, a spokeswoman in the bureau's Seattle office.
Niebusch said investigators have begun processing the women's vehicle for evidence and have received dozens of tips, but released no information about what they've learned so far.
"Our first priority here is to solve a homicide," Niebusch said Friday. "We want to bring a killer to justice. To do that, there are certain details that we cannot bring out into public view." He added they are still asking that anyone with information about the killings call its tipline at 425-388-3845.
Cooper was a librarian at Alternative Elementary No. 2 at Decatur Elementary School in Seattle. A makeshift memorial at the school included five sunflowers and a cardboard sign that read: "Mary in the library - the nicest person in the universe. You will always be in our hearts."
Her daughter had worked for the Audubon Society in Seattle and had jobs in salmon stream enhancement and outdoor education. In 2003 she spent time as a volunteer in Nepal.
A memorial service for the two women is planned for Sunday, July 23.
The family requests that in lieu of flowers donations be sent to:
"In memory of Mary Cooper"
Seattle Public Library Foundation
1000 4th Ave
Seattle, WA 98104
For Children's Literacy Programs
"In memory of Susanna Stodden"
Washington Trails Association
2019 3rd Ave
Seattle, WA 98121
www.wta.org or 206-625-1367