Rhone Glacier, Valley glacier in Valais, Switzerland

Rhone Glacier is a valley glacier in Valais, Switzerland, about 8 kilometres long and roughly 2 kilometres wide on average, covering some 15 square kilometres. It rises on the southwest flank of the Dammastock at around 3600 metres; the upper 2.5 kilometres, called Eggfirn, drop about 600 metres. The tongue ends just above 2200 metres, where the Rhone rises, and a lake has formed behind the rock threshold since 2006/2007, reaching 550 metres in length by 2024.

The glacier's scientific record began in 1874, when engineer Philipp Gosset made the first surveys; Paul-Louis Mercanton published the measurements of 1874–1915 in 1916. Since then the ice has retreated about 8.5 m a year and lost roughly 25 cm of thickness annually. An ice grotto was cut into the tongue near the Furka Pass road and could be visited until 2026, when it had to close.

The glacier gives rise to the Rhône, which flows through Lake Geneva into France. In 1546 the scholar Sebastian Münster described the ice tongue on his way over the Furka Pass, estimating its height at 10 to 15 metres and its width at 200 metres. Pyramidal columns about 1.5 metres high, marked with years from 1815 onward, stand in the Gletsch valley and record how far the ice once reached.

The glacier tongue lies just above 2200 m at the end of the Furka Pass road; from the Hotel Belvédère, closed since 2015, a paid footpath of a few hundred metres leads to it. The ice grotto could be visited until 2026, when the covering of the ice with white sheets was no longer considered permissible and it had to close. The grotto then sat in ice above the glacier's end lake, no longer connected to the glacier.

During ice ages, the tongue reached eastward beyond Lyon in France, with ice piling up to 2000 meters (6500 feet) thick. Today, markers along the trail show where the snout stood in past decades, revealing the pace of retreat.