Ueli Steck is a Swiss mountaineer, born October 4, 1976 in Langnau im Emmental (Switzerland) and died April 30, 2017 in Nepal. Nicknamed the "Swiss Machine", it is known for its solo ascents and speed records.

As a child, Ueli Steck played ice hockey. At 12, he discovered rock climbing and joined the Swiss Alpine Club. At the age of 18, he climbed the north face of the Eiger and the Bonatti pillar in the Mont-Blanc massif. In 1998, he soloed the Haston Couloir on the Mönch in 3.5 hours, and in 1999 the Lauper route on the Eiger in 5 hours. In 2001, he made the first ascent of the west face of Mount Pumori with Ueli Bühler. From 2002, he made several ascents with Stephan Siegrist: "The Young Spider" (2002) and "La Vida es Silbar" (2003) on the north face of the Eiger, then they chained the 3 north faces of the Eiger, Mönch and Jungfrau in 25 hours (2004). In 2005, he made the first solo ascent of the north face of Cholatse (6,440 m) and the west face of Tawoche (6,505 m).

Ueli Steck is regularly talked about thanks to his speed records. In 2007, he set a new Eiger north face record of 3:54, then in February of the following year he broke his own record with a time of 2:47:33.

In May 2008, in full preparation for their excursion to the south face of Annapurna, Ueli Steck and Simon Anthamatten set off to rescue mountaineer Iñaki Ochoa de Olza. A rescue helicopter could not be used at such high altitudes, Ochoa died on May 23. Steck will stay by his side until the end.

On January 13, 2009, Ueli Steck completed a record trilogy (Eiger, Grande Jorasse, Matterhorn) on the north face in 1 hour 56 minutes to reach the summit of the Matterhorn via the Schmid route. He received the Piolet d'Or 2009 in technical difficulty for the first ascent of the north face of Tengkampoche (6,500 m) with Simon Anthamatten. On July 9, he managed his first 8000, the Gasherbrum II (8035 m) solo.

In 2011, on April 17, he climbed the south face of Shisha Pangma (8,013 m) in a record time of 10:30 a.m. and 18 days later, on May 5, he climbed Cho Oyu (8,201m) with Don Bowie. On November 18, 2011, he presented Ueli Steck: Speed, his film in Martigny, Switzerland. In August 2012, Ueli Steck created the Eiger-Mönch-Jungfrau triptych in less than 12 hours. On October 9, 2013, Ueli Steck added to his list of achievements a solo ascent of the south face of Annapurna. During the summer of 2015, Ueli Steck carried out with Michael Wohlleben the #82summits project of more than 4,000 m in the Alps without the use of motorized means, Ueli reached the end of the project in 62 days.

On November 11, 2015, Ueli Steck and Nicolas Hojac climbed the north face of the Eiger via the Heckmair route in 3 hours 46 minutes, thus beating the roped ascent record. On November 16, 2015, 5 days later, Ueli set a new Eiger record of 2:22:50.

On April 30, 2017, Ueli Steck is training for a combined ascent of Everest then Lhotse in less than 48 hours and without oxygen via the West Ridge route, never repeated. He was discovered dead by rescuers, after slipping on a patch of ice and falling 1,000 meters from one of the faces of Nuptse, during an acclimatization ascent.