The Lake of Zug is one of the minor Swiss lakes, on the outskirts of the Alps and north of the Lake of Lucerne. Probably at some former date it was connected by means of the Lake of Lowerz and the plain of Brunnen with the Lake of Lucerne. At present it is formed by the Aa, which descends from the Rigi and enters the southern extremity of the lake. The Lorze pours its waters into the lake at its northern extremity, but 13/4 m. further west issues from the lake to pursue its course towards the Reuss.

The Lake of Zug has an area of about 15 square miles (39 km²), is about 9 miles in length, 21/8 miles in breadth, and has a maximum depth of 650 feet (200 meters), while its surface is 1368 feet (417 meters) above sea-level. Its volume is 3200 million m³. For the most part the lake is in the Canton of Zug, but the southern end is, to the extent of 33/4 square miles, in that of Schwyz, while the Canton of Lucerne claims about 3/4 square miles, to the north of Immensee . Toward the south-west extremity of the lake the Rigi descends rather steeply to the water's edge, while part of its east shore forms a narrow level band at the foot of the Rossberg (5194 feet, 1583 meters) and the Zugerberg .

At its northern end the shores are nearly level, while on the west shore the wooded promontory of Buonas (with its castles, old and new) projects picturesquely into the waters. The principal place on the lake is the town of Zug. Three railways follow the shore of the lake, one from Zürich via Zug and Arth-Goldau to the St Gotthard, one from Luzern via Arth-Goldau to the St Gotthard and one from Zürich via Zug to Lucerne.

Many fish (including pike and carp of considerable weights) are taken in the lake, which is especially famous for an endemic kind of trout (Salmo salvelinus, locally called Rolheli). Due to the impact of agricultural run-off, the Lake of Zug is considered one of Switzerland's less clean lakes.

List of cities and places on the lake

• Zug
• Oberwil
• Walchwil
• Arth
• Immensee
• Buonas
• Risch
• Cham

Historical notes

Back in 1911 a railway (formerly part of the St Gotthard main route) ran along its eastern shore past Walchwil to Arth at its south end, which was connected by a steam tramway with the Arth-Goldau station of the St Gotthard line. This line ran from Arth along the western shore to Immensee, where it bears south-west to Lucerne, while from Immensee another railway led (at first some way from the shore) to Cham, 3 miles west of Zug.

The first steamer was placed on the lake in 1852.