Medicine Lake is the intriguing lake of mystery and Native legends, and the lake before Maligne Lake. Medicine Lake is drained by one of the largest underground river systems in North America. The water level of the lake varies from season to season. It disappears except for a few streams completely every fall. In the spring time the lake water reemerges. Natives once thought that “spirits” were responsible for the dramatic fluctuations in the placid waters. They called it Medicine Lake of course when the Lake reemerges the water looks a bit murky, like medicine in a bottle.