Roseg Glacier, Glacier in the Bernina Range, Grisons, Switzerland

Roseg Glacier (Romansh: Vadret da Roseg) lies on the northern side of the Bernina Range in Grisons, Switzerland. Its accumulation area sits above 3,500 m on the rocky ridge between Piz Glüschaint and I Gemelli, and it is joined to the Sella Glacier to the east. Both flow north into Val Roseg; in 2013 the glacier was 2.5 km long and in 2022 covered 6.38 km².

The glacier has been systematically measured since the 19th century and shows continuous retreat from that period onward. These changes reflect long-term climate trends affecting the Swiss Alps.

The glacier feeds Lej da Vadret, a 1,500 m long and 300 m wide tongue-basin lake formed in the mid-20th century when the Roseg and Tschiervagletscher separated. In August 1954 meltwater and heavy rain raised the lake level by 85 cm, and the overflow eroded the outlet, contributing to the Oberengadin flood damage that summer.

The glacier is reached from Pontresina through Val Roseg; the Chamanna Coaz at 2610 m stands on the slope west of the ice. The glacier tongues end above Lej da Vadret, a 1500 m long and 300 m wide lake formed in the mid-20th century. The lake's outflow feeds the Rosegbach, which flows via the Flaz into the Inn.

The Lej da Vadret, a 1,500 m long and 300 m wide lake below the glacier tongues, formed in the mid-20th century when the Roseg and Tschierva glaciers separated. In August 1954 its level rose 85 cm after snowmelt and heavy rain, and the overflow eroded the outlet and fed floods in the Upper Engadin.