Born in Saas-Fee, Andenmatten was the winner of the first classical glacier downhill skiing from the Allalinhorn down to Saas-Fee in 1946 (time: 8:07 min.). As a soldier he participated in the demonstration event, military patrol. He had the military rank of a Kanonier at this time. His Swiss team (R. Zurbriggen, H. Zurbriggen, Vouardoux, Andenmatten) finished first in the military patrol event. In 1947 he, Robert Zurbriggen, Karl Hischier and Karl Bricker also won the revenge race in Oslo. As of 2008 he still participated in ski races, for example as the eldest competitor of the Saas-Balen valley race on February 17, 2008.