Results of the activity of Quaternary glaciations in the western Baikal area are considered based on new factual material. Also, the problem of the formation of “watershed pebbles” in the area is discussed. Data indicating the fluvioglacial origin of the pebbles are reported. Special attention is given to the composition, lithology, and stratigraphy of glacial deposits and their geomorphologic position in the study area, which is one of the most hardly accessible and interesting regions in East Siberia in terms of both the geology of Quaternary deposits and archaeology. Results of spore-and-pollen analyses and archaeological evidence are reported.