Aron Lee Ralston (born October 27, 1975) is an American mountain climber and public speaker. He gained fame in May 2003[1] when, while canyoneering in Utah, he was forced to amputate his lower right arm with a dull knife in order to free himself after his arm became trapped by a boulder.
The incident is documented in Ralston's 2004 autobiography Between a Rock and a Hard Place, and is the subject of the 2010 film 127 Hours.