Maligne Lake water pools in Medicine Lake on its way underground to Athabasca River, Jasper, AB
wiki: Medicine lake is a geologic anomaly in the sense that it is not actually a lake but rather an area in which the Maligne River (flowing from Maligne Lake into the Athabasca River) backs up and suddenly disappears underground. During the summer months during intensified meltwater runoff the lake (which during the winter months is a meandering frozen river) fills to levels which fluctuate over time and with the runoff events.