It comprises the upper Linth valley, and the entire Sernf valley, and includes the villages of Betschwanden, Braunwald, Diesbach, Elm, Engi, Haslen, Hätzingen, Leuggelbach, Linthal, Luchsingen, Matt, Mitlödi, Nidfurn, Rüti, Schwanden, Schwändi and Sool.

The municipality of Glarus Süd was created on 1 January 2011, incorporating the former municipalities of Betschwanden, Braunwald, Elm, Engi, Haslen, Linthal, Luchsingen, Matt, Mitlödi, Rüti, Schwanden, Schwändi and Sool.

At the time of its creation, Glarus Süd was the largest Swiss municipality by area.

With the exception of the resort village of Braunwald, all the centres of population of the municipality lie in one or other valley.

Heading upstream from Mitlödi along the valley of the Linth, the villages of Sool, Schwändi, Schwanden, Nidfurn, Haslen, Leuggelbach, Luchsingen, Hätzingen, Diesbach, Betschwanden, Rüti and Linthal are encountered.

Heading upstream from Schwanden along the valley of the Sernf, the villages of Engi, Matt and Elm are encountered.

[8] The historical population is given in the following chart:[10] There are thirteen Swiss heritage sites of national significance located in the new municipality.

[11] In 1981, the Wakker Prize was awarded to Elm for the development and preservation of its architectural heritage.

In the 17th and early 18th centuries, beef cattle were pastured in the Alps in summer for export to Italy.

There is also an hourly St. Gallen S-Bahn service S6 to and from Rapperswil, which serves Mitlodi before terminating at Schwanden.

[14][15][16] Sernftalbus operates an hourly bus service linking Schwanden station with communities in the valley of the Sernf river, including Engi, Matt and Elm, following the route of the Sernftal tramway that ran between 1904 and 1969.

PostAuto Schweiz operates a service from Linthal station to Flüelen station, on the Gotthard railway and Lake Lucerne, which provides several daily return journeys across the Klausen Pass between June and September.

The wettest month was August during which time Braunwald received an average of 206 mm (8.1 in) of precipitation.

The wettest month was August during which time Elm received an average of 171 mm (6.7 in) of precipitation.