The lake serves as a reservoir for the local hydroelectric power plant operated by Axpo.
The valley is considered a site of geological significance due to the Glarus Thrust, a UNESCO World Heritage site nearby.
The depth of the lake reaches approximately 47 meters at its maximum point.
During winter, the lake surface frequently freezes, though ice thickness varies, making public skating dependent on local safety assessments.
The lake is fed primarily by the Klön river, originating from the surrounding mountain glaciers.
It is frequently cited as one of the oldest reservoir-utilized lakes in Switzerland.
The surrounding cliffs reach heights of over 1,000 meters above the lake surface.
Klöntalersee is a natural alpine lake situated at 848 meters above sea level in the canton of Glarus, Switzerland. The lake is a reservoir formed by the natural damming of the Löntsch river and the construction of the Hinter-Klöntal dam, completed in 1908. It is renowned for its turquoise water, which reflects the surrounding steep limestone peaks of the Glarus Alps. The area offers multiple designated campgrounds along the shoreline, accessible for tents and camper vans. The water temperature is generally cool, though it remains a popular site for swimming during the summer months. Geologically, the lake sits within a deep, glacially carved valley. Visitors can access various hiking trails that lead from the lake perimeter into the surrounding high-altitude terrain. The site remains a primary regional hub for outdoor recreation, including fishing, rowing, and cycling.
The eastern shore near the dam provides a panoramic view of the length of the lake against the backdrop of the Glärnisch massif.
Bring sturdy footwear if planning to hike the trails surrounding the steep valley walls.
Ensure all trash is removed as the area is a protected natural environment with limited waste facilities.
The water is cold even in peak summer; bring a wetsuit if you plan to swim for extended periods.
Attempting to swim in areas near the dam wall, where currents and water intake flows can be dangerous.
The mountain road access may be restricted or closed during winter months due to avalanche risk or heavy snow accumulation.
Respect quiet hours in designated camping zones and keep noise levels low to preserve the natural soundscape.
