Taking into consideration new data in paleoglaciology, geomorphology, till stratigraphy and the provenance of erratics in the northern periphery of Western Siberia, and data on the absolute ages of lacustrine sediments, the authors conclude that vast glacier‐dammed lakes, contemporaneous with the last (Sartan) glaciation, existed in the West Siberian Plain. These lakes discharged southwestward via the Turgay Gate into the Aral‐Caspian basin.