Gangotri Glacier, Himalayan glacier in Uttarkashi district, India

Gangotri is a valley glacier in Uttarkashi district, India, about 30 kilometres long and 2 to 4 kilometres wide, flowing northwest from a cirque below Chaukhamba. Its ablation zone is buried under thick supraglacial moraine, with ice cliffs and meltwater pools breaking through the debris. The terminus, Gomukh, is the source of the Bhagirathi river.

The Gangotri Glacier has been receding since measurements began in 1780. Between 1936 and 1996, the front withdrew 1,147 metres, an average of 19 metres per year. In the 25 years up to the 21st century, retreat exceeded 850 metres, about 34 metres per year.

The glacier terminus is called Gomukh, meaning cow's mouth, referring to the shape in which the ice opens to release the river. Pilgrims gather here to pray at the water's edge and collect what they believe to be sacred water.

The trek to the glacier passes through Devgadh, Chirbasa and Bhojwasa, with overnight stays possible only in Bhojwasa. Hikers should prepare for cold temperatures and thin air at high altitude.

Multiple meltwater lakes form on the glacier surface where the ice starts to melt from sun exposure. These pools feed streams that carve their way through the ice and drain toward the river.