The Trona Towers are near the mining town of Trona, California, southwest of Death Valley National Park. These unusual pinnacles are massive deposits of tufa and travertine (forms of freshwater limestone) that formed where calcium-carbonate rich waters discharged from submerged springs into a large, salty lake that filled Searles Valley during the ice ages of the Quaternary. Tufa towers like these near Trona are still forming in Mono Lake today.