Unterkircher was born in Sëlva. In 2004, he was the first alpinist to climb the two highest peaks on Earth (Mount Everest and K2) without oxygen in the same year (within 63 days) he made the second ascent of Mount Genyen, China, (first ascent by Japanese in 1987) and the first ascent of the North face of Gasherbrum II (together with Daniele Bernasconi and Michele Compagnoni). He also climbed the Jasemba, Nepal, (together with Hans Kammerlander). He received several awards including the Cavaliere Ordine al Merito della Repubblica Italiana.