"A conspicuous feature of the Kawdy Plateau west and southwest of Tuya Lake are the flat-topped, steep-sided volcanoes, called tuyas, which are built up on the plateau surface. There are seven or more in the area, and the higehst of them, Kawdy Mountain (6,372'), rises almost 2,000 feet above the local plateau level.

"The tuyas consist of nearly horizaontal beds of basaltic lava capping otuward-dipping beds of fragmental volcanic rocks; they have a most interesting origin. It is thought that they were formed by volcanic eruptions which had been thawed through the Pleistocene ice-sheet by underlying volcanic heat. The lavas capping the mountains were extruded after the volcanoes were built above lake-level, and the outward-dipping beds were formed by the chilling of the lava when it reached the water's edge."