Abstract <p>The paper discusses landscape evolution in a broad transitional zone between the Western Sayan and Altai mountain structures in the context of cataclysmic and gradual geomorphological processes. This region hosts a global watershed between Arctic Ocean and Mongolian inland drainage basin. The distribution of glacial landforms and deposits there indicates vast late Pleistocene glaciation included large ice sheet at the Shapshal Range, ice cap on the Mongun-Taiga massif and valley glaciers in the Chikhachev Range. The ranges are separated by Dzhulukul depression, Kargy and Mogen-Buren River valleys which show different scenarios of deglaciation and further evolution of post glacial landscapes. Gradual non-cataclysmic deglaciation and transformation of the fluvial system was inherent to the Kargy River basin. The neighboring Mogen-Buren River basin exposes landscape affected by cataclysmic outburst floods from ice-dammed lakes. Another specific deglaciation feature is redirection of the water runoff from the Dzhulukul depression from the south to north. The early-middle Holocene landscapes of the region developed under more humid and warm climate conditions. Various proxy data: lacustrine sedimentation patterns, chironomid and vegetation change records, paleosoil archives indicate abrupt climatic changes in the second half of the Holocene towards colder conditions and intensified aridity, which is especially pronounced for the last 2–1.5 ka. Despite scattered single Paleolithic finds of loose time constraints, this severe land became regularly populated since the Bronze Age.</p>