At highstand Lake Suguta had a roughly rectangular shape with the long side trending north-northeast from Emuruangogolak volcano in the south to The Barrier in the north, and between the Loriu Plateau west and Tirr Tirr Plateau east of the valley. The lake covered a total area of and was about deep. The Pliocene-Pleistocene Namarunu volcano formed a peninsula on the western coast, while the Kamuge River valley at the southwestern end of the lake was occupied by a bay. A cinder cone formed an island at the northern end of Lake Suguta and was reached by humans, judging by the presence of obsidian artifacts; traces of human activity have also been encountered