A 21-year-old New Jersey hiker died of hypothermia near the summit of Mount Marcy after slipping off a trail during a solo winter trek with her dog, authorities confirmed this week.
Brianna Mohr of Brick, New Jersey, called 911 at 3:05 p.m. on Thursday, February 12, to report she had slipped near the peak of New York’s highest mountain and couldn’t get back to the trail. Despite an extensive six-hour search operation involving snowmobiles and helicopters, forest rangers discovered Mohr deceased at approximately 9:51 p.m., according to New York State Police.
Her dog was found alive and uninjured beside her body. Rangers hiked the animal out to safety.
Temperatures in Keene, New York, where the 5,344-foot peak towers over the Adirondacks, ranged from -8 to 20 degrees that day. By 9 p.m., temperatures had plunged to single digits with wind chills hovering around zero at lower elevations — conditions were almost certainly harsher near the exposed summit where Mohr was stranded.
An autopsy conducted February 14 at Glens Falls Hospital by forensic pathologist Dr. Michael Sikirica determined hypothermia caused Mohr’s death, State Police said.
The rescue effort began immediately after Mohr’s distress call. DEC forest rangers deployed ground teams with snowmobiles and a tracked utility vehicle while the New York State Police Aviation Unit launched a helicopter for a potential hoist rescue. Two rangers attempted to spot the hiker from above, but heavy cloud cover blanketing Mount Marcy’s exposed summit prevented any sighting.
At 6:06 p.m., one ranger who had been in the helicopter was inserted at the Marcy Dam Outpost, roughly 5.1 miles away and nearly 3,000 feet below the summit. From there, the ranger hiked upward through brutal conditions toward Mohr’s last known location near the peak. The ranger reached her just before 10 p.m. — but she was already gone.
Poor weather conditions initially prevented rangers from removing Mohr’s body from the mountain. Early Friday morning, a State Police helicopter inserted two forest rangers at the site to recover her remains.
In an online post Sunday, a relative shared additional details, revealing that Mohr had experienced disorientation from hypothermia before her death. “All this to say PLEASE be careful and turn around/call the rangers if you feel unsafe for ANY reason,” the post read.
“The New York State Department of Environmental Conservation offers its condolences to the family,” a DEC spokesperson said in a statement.
Friends described Mohr as an avid hiker who loved the outdoors. Her Instagram account, featuring simply a mountain and heart emoji in its description, showcased breathtaking adventures across the country — from Death Valley to Yellowstone, Mount Washington in New Hampshire to Rocky Mountain National Park, Moosehead Lake in Maine to Canyonlands National Park in Utah. She had previously posted photos from Marcy Dam during a December visit to the Adirondacks.
Mohr was a 2022 graduate of Brick Memorial High School. On Monday, February 16, her brother Ryan shared a heartbreaking tribute.
“You were the best friend and sister I could have ever asked for,” Ryan wrote. “You are the reason I am the person I am….I love you forever Bri. Rest in peace.”
Mohr’s mother, Stephanie West, posted a photo tribute to her daughter on Valentine’s Day — the same day the autopsy was completed.
“I am so lost,” West wrote alongside a broken-heart emoji.
Mount Marcy presents formidable challenges even for experienced winter hikers. At 5,344 feet, New York’s tallest peak features an alpine summit prone to extreme weather conditions, including low visibility from clouds and blowing snow, frigid wind chills, and deep snow pockets that create dangerous “spruce traps” — hidden air pockets that form when snow falls around short summit pine boughs, creating sinkholes when stepped over.
Strong winds can quickly erase any existing snowshoe tracks, making navigation especially difficult on the exposed summit. The DEC reported Wednesday that snow depth at its Lake Colden Interior Outpost cabin, about 3 miles west of Mount Marcy and nearly 2,600 feet below its summit, measured 49 inches. Snow depth typically increases with elevation.
The standard Van Hoevenberg Trail route to Mount Marcy’s summit involves a challenging 14.8-mile round-trip journey with more than 3,000 feet of elevation gain. The mountain attracts tens of thousands of hikers annually, making it one of the most popular destinations in the Adirondacks — though winter ascents require specialized gear, including snowshoes and crampons, and experienced hikers recommend never venturing alone.
Authorities have not disclosed what caused Mohr to slip or whether she was already suffering from the effects of hypothermia before her fall — though the relative’s account suggests disorientation may have played a role in the tragedy.