The «Chüebodengletscher» lies on the main watershed boundary of the Swiss Central Alps. Earlier, its two glacier tongues flowed out on both sides (to the NW, Gerentaal, Valais and to the S, Val Bedretto, Ticino). Now these two tongues have disappeared, and a surface lake began to form around the year 2000. This one became increasingly larger until November 2020, and a lifting and calving of the glacier tongue occurred. Various observations and measurements show us a general picture. This includes information about the future small, but deep circular mountain lake, lying in a «kar», which was most likely glacially carved from two directions: from south generally, and from northwest.