The Oberrhätkalk is very difficult to find on the gravel banks of the Lech River because it is very similar to the Wetterstein Lim estone. It was formed by marine sedimentation between the Triassic and Jurassic geological eras. At this time, the living conditions in the sea have improved, so that large coral reefs were formed.

These coral deposits gave rise to the Oberrhätkalk, which is popular with climbers due to its low stratification and strength.