Question: Which American rock climber responsible for locating the body of George Mallory on Everest failed in his attempt to climb over the west ridge of Mount Epperly?
Sentence (from "2007 Altitude Everest expedition"): The 2007 Altitude Everest expedition, led by the American climber Conrad Anker, arrived at Base Camp below the north face of Everest in May 2007 and retraced the last journey of British climber George Mallory.
Relevant evidence: No