The southern portions of western Siberia stretch from the eastern Urals region in the west to the Yenisei River in the east, and from the taiga geographical zone in the north to the border between Russia and Mongolia (Central Asia) in the south. This territory can be subdivided into several ecological zones: The taiga zone in the north borders the forest-steppe zone. The forest-steppe is replaced by the steppe zone. The southernmost portion is the mountain taiga zone of the Altai and western Siberia.
All these zones were formed during the Holocene. Apparently, climatic fluctuations may have shifted the boundaries of ecological zones either to the north or to the south during the history of development of this region.
The region contains large and small rivers. Availability of freshwater was beneficial for human habitation throughout the historical periods. Great Siberian rivers like the Ob, the Irtysh and the Yenisei flow from south to north. Smaller rivers like the Tobol, Ishim, Om, Tara, Chulym and others flow in a latitudinal direction. There is a large Lake Chany that was really a sea during the high-water periods.
Southwestern Siberia was rich in natural resources: various species of wild animals, birds and fish. The region is also rich in mineral resources. Woods provided people with timber, grasses, berries and mushrooms. The environmental conditions allowed humans to hunt, fish and forage. Later, with the development of a productive economy, people started animal husbandry and agriculture. Mineral resources in the southern parts of west Siberia made it possible to produce bronze and iron during later periods.