Селенга
During 1928 and 1929, G. P. Sosnovskii, under the purview of the Academy of Sciences of the U.S.S.R directed an archaeological Stone Age study in the Selenga Valley near Kiakhta. In this expedition, Sosnovokii discovered remains of local Paleolithic culture in an area that stretched from "the valley of the Selenga River from the Mongolian Frontier down to Selenginsk."