Gries Glacier, Alpine glacier in Valais, Switzerland.

Gries Glacier is an ice formation in the Lepontine Alps that covers a substantial area across different elevations. The surface displays typical glacier features including crevasses and moraines that reveal the slow movement of ice over time.

During World War II, the Swiss Army built fortifications near the glacier to monitor the border with Italy and protect the region. These military structures remained as historical reminders of that period.

The glacier's name comes from the Griesbach stream that drains it; the stream joins the Ägene, which flows into the Rhône near Ulrichen in the Goms. During the Little Ice Age, from the 16th to the 19th century, the ice overlapped the 2,479 m Gries Pass and pushed a short tongue south into Italy's Valle del Gries.

Hiking trails provide access from mountain passes to viewing areas where you can observe the glacier from safe distances. Sturdy footwear is essential, and it is best to visit during stable weather conditions.

The glacier's tongue reached the dammed Griessee at about 2,400 m until around 2001; the reservoir then decoupled the ice from its bed and sped up the retreat. The Griesbach drains the glacier and joins the Ägene, which flows into the Rhône near Ulrichen in the Goms.