The river rises in the High Tauern range of the Central Eastern Alps on the Pasterze Glacier at the foot of the Grossglockner, the highest mountain in Austria. It discharges after near Möllbrücke into the Drava. At the beginning of its course, at the southeastern end of the Pasterze Glacier, it is impounded to form the Margaritze Reservoir, from where part of the water is diverted via pressure tunnels across the Alpine crest and Mt. Wiesbachhorn to the reservoirs of the Verbund hydroelectric power plant in Kaprun, Salzburg.