Griesssee is a new proglacial lake which started to form around 1980 due to the recession of Clöaridengletscher-N at the base of Clariden, a 3267m high peak in the Glarus Alps, Switzerland. The frontal part of the glacier today is mostly debris-covered; it is fed mainly by avalanching from the Clariden north face. The lake had grown to a width (E to W) of about 350 metres and a length (N to S) of about 300 metres in 2011.