Nelson, 49, is described by her sponsor, The North Face, as “the most prolific ski mountaineer of her generation”.
A decade ago, she became the first woman to summit both the highest mountain in the world, Everest, and the adjacent Lhotse peak within the span of 24 hours.
In 2018, she returned to Lhotse and made the first ski descent of the mountain, which earned her the National Geographic Adventurer of the Year award.
In an Instagram post last week, Nelson said her latest climb had been deeply challenging because of “incessant rain” and dangerous conditions.
“I haven’t felt as sure-footed on Manaslu as I have on past adventure into the thin atmosphere of the high Himalaya,” Nelson wrote in a post on Thursday.
“These past weeks have tested my resilience in new ways.”
“LET’S PRAY FOR HILAREE”
Mountaineers and well-wishers had earlier shared messages of support on social media, hoping for Nelson’s safe return.
“Let’s pray for Hilaree,” fellow The North Face athlete Fernanda Maciel, currently at the Manaslu base camp, wrote on Instagram on Tuesday.
Constant rain and snow have been a challenge for the 404 paying climbers attempting to reach the summit of Manaslu this year.
On the same day as Nelson’s accident, an avalanche hit between Camps 3 and 4 on the 8,163m mountain, killing Nepali climber Anup Rai and injuring a dozen others who were later rescued.
The deaths of Nelson and Rai are the first confirmed casualties of the autumn climbing season in Nepal.
Nepal is home to eight of the world’s 14 highest peaks and foreign climbers who flock to its mountains are a major source of revenue for the country.
The industry was almost completely shut down due to the COVID-19 pandemic in 2020, but the country reopened its peaks to mountaineers last year.