[2] On April 27, 2010, she reached the summit of Annapurna;[3][4] upon doing so, she claimed to have climbed all fourteen eight-thousanders, which would have made her the first woman to achieve this feat.

[9] The mountaineering site ExplorersWeb officially considers the Basque Edurne Pasaban as the first woman to have successfully climbed all fourteen peaks.

A previous attempt in October 2009 came up 500 meters short when a blizzard made further ascent impossible.

On April 23, Oh reached camp C3, located at 6,400 m, but was forced to retreat the next day due to wind.

[6] Congratulating Oh on her accomplishment, South Korean president Lee Myung-bak said, "She showed us what challenge means".

[15] After doubts were first raised in Korea, Oh held a press conference in which she tearfully remarked that the blurriness "was unavoidable due to fog and a violent snowstorm.

[15] In April 2010, Oh's main rival, Edurne Pasaban from Spain, who was also aiming to become the first woman to climb all fourteen eight-thousanders, weighed in on the controversy.

[15] On April 24, Hawley explained her decision, "The only picture that anyone has seen shows Miss Oh standing on bare rock.

But Miss Pasabán (who was on the mountain at the same time) showed me a picture of her team on the summit, and they are standing on snow.

[14][15] Ferran Latorre, a Spanish climber, claimed that the green rope affixed to the mountain by Oh's team (visible in the picture) stopped 200 meters short of the summit.

[15] Eberhard Jurgalski of 8000ers.com, a website devoted to keeping mountaineering records, said, "It's all mixed up, you cannot say what is true and what's invented.

[16] The organization concluded that "doubts about Miss Oh's Kanchen summit were not backed by enough fact", but said it would be happy to review any new evidence the involved parties had to offer.

[16] According to a press release by Black Yak, there were several teams on the mountain at the time and none of them doubted Oh's summit then.

[16] At the time, Pasabán herself wrote "Korean Oh Eun Sun just reached the top in spite of the wind.

[19] Oh claimed that Korea's KBS Television had video and picture evidence of her summit that had not yet been made public.

[20] On May 23 Pasabán conceded that she was the second woman to climb world's 14 highest peaks, but still questioned whether Oh actually held the record[clarification needed].

[7] On August 26, 2010 the Korean Alpine Federation (KAF) judged that Oh "probably failed" to reach the top of Kangchenjunga.

[25] BBC News also reported on 27 August 2010 that "A member of the next team to reach the peak of Kangchenjunga, in May 2009, the Norwegian climber Jon Gangdal, says he found Ms Oh's Korean flag weighed down by stones, some 50m or 60m below the summit.

"[7] Oh has used helicopters to travel between base camps, and employed teams to prepare for her ascents in advance.

[13] Oh was criticized for failing to come to the aid of ailing Spanish climber Tolo Calafat, who died on Annapurna while waiting for help.