Hilaree Nelson.Photo: Hilaree Nelson/Instagram

American ski mountaineer Hilaree Nelson is missing in Nepal after reportedly falling into a crevasse while descending from the peak of a mountain.
On Monday, Nelson, 49, and her partner Jim Morrison ascended the peak of Manaslu, an 26,781-foot mountain that stands eighth-tallest in the world, with three Sherpa guides before they attempted to ski down from the summit, reportedThe New York Times.
A quarter-hour after Nelson and Morrison started skiing, however, the group radioed the manager of expedition organizers Shangri-La Nepal Trek to report that Nelson appeared to fall into a 2,000-foot crevasse, reportedOutsidemagazine.
“The duo reached the true summit of Manaslu at 11.30 A.M. local time. And about 15 minutes later I got a call from our staff at Base Camp that her ski blade skidded off and [she] fell off the other side of the peak,” Jiban Ghimire, managing director of Shangri-La Nepal Trek toldOutside
Hilaree Nelson and Jim Morrison.Niranjan Shrestha/AP/Shutterstock

Eyewitnesses toldThe Himalayan TimesMonday that Nelson appeared to fall roughly 80 feet into the crevasse during the accident. It is unclear whether she may have survived the fall.
Morrison continued skiing down the mountain to seek help at a base camp Monday, but Ghimire toldThe Timesthat inclement weather was “hampering search and rescue operations.”
Ghimire added that his company would send a helicopter early Tuesday morning to the crevasse Nelson disappeared into and that Morrison would join the rescue mission so long as the weather proved fair enough to fly, according toThe Times.
Never miss a story — sign up forPEOPLE’s free daily newsletterto stay up to date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
Last Thursday, Nelson shared a series of photos onInstagramshowing her group’s journey up and down the mountain, adding that inclement weather had prevented the group from attempting to reach the summit.
“These past weeks have tested my resilience in new ways. The constant monsoon with its incessant rain and humidity has made me hopelessly homesick,” Nelson wrote on Instagram. “I am challenged to find the peace and inspiration from the mountain when it’s been constantly shrouded in mist. Yesterday we ended our summit bid when we decided it was too dangerous to move from C3 to C4.”
“We subsequently decided to ski down from C3 knowing that would mean carrying our skis all the way back up the mountain again if, big if here, we try again for a summit,” she added. “It was the best thing we could’ve done.”
View of the mountains near the village of Bimthang in Nepal.Leisa Tyler/LightRocket via Getty

Nelson’s website, which adds that she was namedNational Geographic’s 2018 Adventurer of the Year, states that she “is an avid proponent of wild places such as the Arctic National Wildlife Refuge and holds to the philosophy that these places have huge significance in the well-being of both the planet and the human psyche.”
On Monday, an avalanche further down Manaslu hit a separate climbing expedition, killing one person and injuring 14 more, according toThe Times.
source: people.com