Marion County Sheriff's Office officials said more than 340 searchers spent seven days scouring more than 350 square miles of terrain in the Willamette National Forest for any sign of Zickel. The Oregonian reported that snow complicated the search, which took place in terrain between 5,000 and 7,500 feet above sea level.
Despite thousands of hours of effort, searchers came up empty-handed.
Zickel remained missing for three years, until Marion County officials received a call three weeks ago from a group of climbers who reported they'd found human remains and personal effects in a glacial area above Jefferson Park. They believed them to belong to Zickel.
Zickel had last been spotted by other hikers on the Pacific Crest Trail, just north of Jefferson Park, before he vanished, The Oregonian reported. His vehicle was found parked near a trailhead four days later.
Riley Zickel, 21, of Sebastopol, Calif., went missing July 30, 2016, on a hike in Oregon's Mount Jefferson Wilderness area. The remains of the Lewis & Clark College student were found Tuesday, Sept. 3, 2019, in a glacial area of the mountain.
"The area where he was located is extremely steep with loose rocks and rock avalanches, making this an extremely challenging recovery effort," Sheriff's Office officials said in a news release. "Marion County Sheriff's Office Search and Rescue partnered with Corvallis Mountain Rescue, the Civil Air Patrol and the United States Forest Service to plan today's recovery mission."
Zickel’s father, Robin Zickel, was waiting at the trailhead as the remains were brought out of the wilderness. Along with a positive identification, the Zickel family and law enforcement officials are awaiting word on his cause of death.
Foul play is not suspected, authorities said. The condition of Riley Zickel's remains was not made public.
Once the remains are conclusively identified, Robin Zickel will bring his son’s body home to Sebastopol, a city about 8 miles outside of Santa Rosa in Sonoma County.
Robin Zickel said the area in which his son’s remains were discovered had been searched three years ago but could not have been searched well.
"It's in very rockslide-prone terrain," he told the Press Democrat.
He said his son’s clothing and gear also blended in with the terrain, which likely made the 2016 search even more difficult.
Riley Zickel, described as an avid backpacker, graduated from Analy High School in Sebastopol before studying chemistry and music at Lewis & Clark College, where he had a partial music scholarship. He played in the college's orchestra and jazz groups, Robin Zickel told the Press Democrat in 2016.
The Zickel family held a memorial service for Riley Zickel in October 2016, several months after he went missing, the Press Democrat reported. At the time, his mother, Erin Zickel, said they were coping with their loss.
"The truth of it is, he was only 21," Erin Zickel said at the time. "But it's kind of a beautiful story in the sense that he died doing something he loved so much more than anything in the world, and now he is literally part of the mountain."
In March, on what would have been his son’s 24th birthday, Robin Zickel wrote on Facebook that nature was where Riley found refuge. He said he learned from his son constantly and still does, despite his absence.
On July 28, the anniversary of Riley’s disappearance, Robin Zickel echoed that sentiment.
“Riley, not a day goes by that I don't think of you. You taught me what’s most important to me and now I live the way I have always wanted to live,” he wrote, thanking his son.
Marion County Sheriff Joe Kast expressed thanks to everyone who helped bring the search for Riley Zickel to an end.
“We are grateful to the many organizations that helped make today’s recovery of Mr. Zickel possible,” Kast said Tuesday in a statement. “Without their contributions, we would not have been able to bring closure to the Zickel family after these three long years.”
Robin Zickel told the Press Democrat Wednesday, as he drove home from Oregon, that knowing for certain his son is dead is painful, but still better than the limbo the family had been in prior to last month's discovery.
"I believe that when you suffer a loss, you learn to live with it. You never get over it, but you learn to live with it," Robin Zickel said. "I was not able to learn to live with not knowing what happened."