 Several tephra layers have been identified, including the 2.003 million years old Huckleberry Ridge Tuff, the 706,000 years old Bishop Tuff and the 602,000 years old Lava Creek Tuff as well as the 2, 1.2-0.8 million years old Glass Mountain tuffs.They form tuff layers which are very conspicuous in the lake sediments.A number of fossils were discovered in the sediments, including "chara", diatoms, ostracods, snails and vertebrates.