Its source is located in the Austrian state of Vorarlberg, where the river rises from the Formarinsee (a lake) in the Alps. It runs northwards and crosses the German border forming the Lechfall, a 12 m high waterfall; afterwards the river enters a narrow gorge (Lechschlucht). Leaving the Alps, it enters the German state of Bavaria, runs through the city of Füssen and behind through the Forggensee (a lake).
The river flows further northwards through a region called the Lechrain and passes the cities of Schongau, Landsberg, Augsburg and Rain before entering the Danube close to Donauwörth.
Lech is also: