The glacier is the largest by area and the third largest by volume of any glacier within this mountain range. It descends for 2,000 metres from the accumulation zone, which lies on the Italian border, and stretches along an estimated 7 kilometre path. The accumulation zone is located below the ridges between the mountains of Bernina (4,049 m), Argient (3,954 m), Zupo (3,996 m) and the Bella Vista Ridge which form part of the main watershed between Switzerland and Italy. The Morteratsch Glacier is overlooked by the Morteratsch Mountain (3,751 m) and is joined just south of a rocky outcrop known as Isla Persa, by the Pers Glacier, which flows from an accumulation zone between the mountains of Palu (3,900 m) and Cambrena (3,606 m). The Morteratsch Glacier is a typical valley glacier and flows from its southern accumulation zone to the north where the tongue of the glacier terminates in a small stream and a large moraine field. The melt-water stream from the glacier drains into the Inn River.