They had a plan for the perfect day—hike a trail on Mount Pilchuck, spot lots of birds and keep going until their feet gave out. But what really made July 11 special for Mary Cooper, 56, and her daughter Susanna Stodden, 27—both huge nature lovers—was the chance to spend it together. "Susanna probably hikes once a week but Mary is pretty busy during the year," says Mary's husband, David Stodden, 57. "So I remember how happy Mary was that morning when she left to go on the hike."

Only hours later both women were dead, shot and killed on a popular trail in Mount Baker-Snoqualmie National Forest in Washington State. A hiker recalled seeing them on the trail at 10 that morning; another came across their bodies around 2:30 p.m. and called police. Investigators say that robbery was apparently not a motive—Cooper's 1997 Dodge Caravan was found where she parked it at the trailhead—and are looking into several scenarios. One is that the killer may have been a crystal meth addict (the nearby town of Granite Falls has had so many drug problems it's been called Methville); another is that the murders may somehow be linked to the shooting of two Oregon hikers one year earlier. So far, though, police have no major clues or compelling leads. "Our goal is to catch a killer," says Snohomish County sheriff spokesman Rich Niebusch, "and to make them answer for what they've done."

Those who knew the women say they were both gentle, compassionate souls. "If Mary had soup, she would bring some to an elderly neighbor," says David, a contractor. "If someone needed a ride somewhere, she would just do it." Susanna belonged to Voluntary Simplicity, a movement whose members vow to live simply and avoid buying products they don't need. Both women had extremely sunny outlooks on life—something that makes their murders more unfathomable. "They never had enemies and they never would have thought of having an enemy," says David. "It was obviously a pretty depraved person who did this. What other explanation is there?"

Another terrible irony is that Susanna and Mary met their end in just the sort of peaceful place they taught others to appreciate. Mary, who raised her three daughters in Seattle's scenic Green Lake neighborhood, was a librarian known for captivating children with her story readings at the AE II Elementary School in Seattle. Passionate about the outdoors, she advised friends and colleagues on the best trails to hike. "She sought out places that were a little bit of a challenge and more remote and beautiful," says the school's principal, John Miner. "She'd go where there weren't lots and lots of people."

Mary and Susanna were close. David recalls that Susanna was a big fan of world music, and the two had attended an African music concert for her birthday. Mary passed on her love of nature to her daughter, who even as a child took an interest in her environment. "One time when [Susanna] was in the eighth grade I was jogging by this playfield and she was with this group painting the play-set," remembers her father. "I bet she's removed weeds from every park in Seattle." In 2001 Susanna graduated from Western Washington University in Bellingham with a degree in environmental education, and last month she finished a stint at the Seattle Audubon Society, where she lectured elementary school children about appreciating nature. "She taught me and everyone she came in contact with to just be in the space that you are in," says her friend Kristen Kosidowski. "She had a very contagious way of being genuine."

Mary and Susanna set out on their hike around 8 a.m. Two other hikers, a man and his wife, ran into them at the start of the trail. "They seemed like exceptionally nice people, and if we had had the same itinerary, we may have hiked with them," recalled the man, who declined to give his name. Not much later, his wife heard what sounded like distant thunder but which they now think could have been gunshots.

When Mary still hadn't returned by 7:30 that evening, David called her cell. "I was definitely concerned," he says. "I grabbed my ice ax and I headed out to go look for them, and that's when the sheriff drove up." As police continue to hunt for clues, friends and colleagues are organizing memorials and tributes to the women; one plan calls for the school library to be named after Mary.

Their family, too, found a way to honor them. Three days after the murders, David and his two other daughters, Elisa, 24, and Joanna, 21, hiked a trail not far from the crime scene, as a way of confronting the terror that had come into their lives. "We went to a lake nearby, and Joanna and I went for a swim and it was a really beautiful day," says Elisa. "We felt it was important to go where we were afraid to go."

Others, though, are still too shaken by a mysterious evil to let go of their fear just yet. "I'm guessing they were in the wrong place at the wrong time with someone with so little value for life that they did the unthinkable," says Miner. "I hope for all of our sakes the police find an answer."

  • Contributors:
  • Howard Breuer/Seattle.