Trettach

Trettach is a river in Bavaria, Germany, located in the Allgäu Alps. It rises in the high mountain terrain near the Austrian border, and flows generally north through the Oberstdorf area. The river passes through the Trettachklamm, a narrow gorge that is a major natural attraction and that contributes to the local scenery.

In its lower course, the Trettach meets the Stillach near Oberstdorf; together they form the Iller, which continues northward through Swabia and ultimately drains into the Danube. The Trettach basin is characterized by alpine valleys, meadows, and forested slopes.

The river is associated with the Trettachspitze, a prominent peak in the Allgäu Alps named after the river. The Trettachklamm is a popular point of access to alpine trails.

The Trettach is part of the Iller-Danube river system and contributes to the hydrology of the region.