Gemsstock, Mountain summit in Uri, Switzerland

Gemsstock is a mountain in the Lepontine Alps reaching 2961 meters above sea level. Its northern slopes feature glaciers and permanent snowfields that define the mountain's appearance throughout the year.

The Gemsstock is a subpeak of the Chastelhorn, about one kilometre to the south-west, and lies in the Chastelhorn-Pizzo-Centrale chain of the Gotthard group. Its north flank carries the Gurschenfirn glacier, which in summer is covered with foil to slow its melting. The cable car from Andermatt, built in two sections with a middle station at Gurschenalp (2212 m), opened the mountain to skiing; the descent named after Andermatt racer Bernhard Russi recalls the resort's racing tradition.

The Gemsstock is the northern peak of the Skiarena Andermatt-Sedrun, and its steep upper runs are named after local figures: the black B. Russi Run honours Andermatt's downhill world champion Bernhard Russi, while the red Sun Track and the off-piste Guspis loop around the back of the mountain. The five lifts on the mountain were all built by Garaventa.

The cable car runs in two sections from Andermatt (1437 m) to the Gurschenalp middle station (2212 m) and on to the summit; outside winter it operates only in high summer and during the autumn holidays. From the top there are no marked paths, only alpine routes, for example to the Vermigelhütte (2042 m) or over the Gafallenlücke and Lago della Sella to the Gotthard Pass. Before February the north-facing summit stays in shade and is very cold.

The Gemsstock is a north peak, so the sun does not reach its summit before February and skiing is possible there until May. The black run from the top is named after Andermatt's downhill world champion Bernhard Russi, and the untracked route around the back of the mountain is called The Guspis.