Aside from the lakes, marshes and bogs were also formed from the glaciers of the ice age because of the high level of the ground water. In the area of the pass summit, there are various types of bogs. In the area of the pass summit there are mainly fens with some smaller transitional mires and raised bogs. On the Kornock there is a vale moor in more than 2,000 m above sea level. The most important bog area adjoins the Schwarzsee and is probably a part of this body of water which has already silted up.