Between six and seven million years ago, a fresh water lake existed there in a forested area with mostly broad leaved deciduous tree species, dominated by sequoia and oak.

The Turkish botany Professor Baki Kasaplıgil (1918-1992) from Çankırı who worked at the Biology Department, Mills College, Oakland, California from 1956 to 1992, made fossil collecting trips to the area around Kızılcahamam - Çerkeş road in 1964 and 1968.

In the 1964 trip he collected fossil leaves of Glyptostrobus, Sequoia, Zelkova, Fagus, Carpinus, Ulmus, Quercus, Tilia and Acer.

In the 1968 trip, he collected 400 plant parts such as leaves, seeds, fruits, twigs and branches.

In 1969, Wayne Fry from University of Berkeley made plant fossil collections in Güvem.