Oetztal Alps, Tirol, mountain range of the Central Alps between Oberinn valley and Etschtal valley, consists of crystalline slate and is the most glaciated of all Austrian mountain ranges. Although all passes and crest depressions are covered with ice, the cultivated regions rise up to an altitude of 2,000 m; extensive pastures for sheep up to 3,000 m. The Oetztal Alps comprise numerous mountain lakes and peaks above an altitude of 3,500 m; the highest elevations are Wildspitze (alt. 3,768 m, the highest mountain of North Tirol), Weisskugel (alt. 3,738 m) and Similaun (alt. 3,599 m), the largest glacier is the Gepatsch Glacier (Gepatschferner), followed by Gurgler Ferner, Hintereis- and Grosser Vernagtferner. The mountains are structured by the upper parts of the Kauner valley, Pitz valley, Oetz valley (all in North Tirol) and Schnalsertal valley (South Tirol). The main crest, which separates South Tirol form North Tirol, has formed the Austrian-Italian border since 1919. The ends of the Kauner valley and the Pitz valley are glacier ski areas; in the Kaunertal valley also power industry (Gepatsch reservoir). Mountain refuges: Braunschweiger Huette (alt. 2,758 m), Taschachhaus (alt. 2,423 m), Brandenburgerhaus (alt. 3,274 m), Vernagthuette (alt. 2,755 m), Ramolhaus (alt. 3,005 m) and others.