Tufa towers along Mono Lake's northern shore. The Mono Laka Tufa Towers were formed when the area was covered with water. Underwater springs rich in calcium chemically reacted with the carbonates in the lake and over a period of decades created these calcium carbonate, or limestone, towers. Some towers reach heights of over 30 feet. The towers were exposed when water was diverted from Mono Lake to Southern California, drastically lowering the water level.