South of Concordia Place the glacier runs towards the valley of the (Upper Valais); on the east side, near , lies a small glacier lake, (); from the western side used to enter the , but since the end cof the 20th century the connection with the Aletsch Glacier has been lost. Further down, until about 1880, the did also enter the Aletsch Glacier at its mouth. But since then both glaciers have been retreating so far that they do not connect anymore (the Upper Aletsch Glacier did retreat about from its connecting point with the Aletsch Glacier), but both serve now only as the source of the river Massa. The river flows through the Lake (a reservoir, and coincidentally representing the glacier's mouth region in the 19th century, which is a retreat of more than ) and a gorge of the same name before reaching the near .