a plains taiga-swamp region in the southern part of Western Siberia. On the west and southwest the region is bounded by the Irtysh River valley and by the Ob’ River valley on the north and northeast. It gradually turns into the Barabin Steppe to the south.

Vasiugan’e is a flat or gently rolling, locally draining plain, slightly inclined to the north and cut by a network of valleys of the Bol’shoi Iugan, Vasiugan, Parabel’, and other rivers. The highest altitude is 166 m; the relative difference in height between the water divides and the valleys is as much as 40-60 m. Vasiugan’e is composed of Neocene sandy-clay deposits; the deposits are covered in the northern sections by boulder clay and Anthropogenic sands and by lake-alluvial loam and sand further south. The water divides are covered with peat bog formations. Up-river stratified pool sphagnum bogs— riamy and gal’i —predominate (48 percent of the territory).

Complex transitions to forests are formed, depending on the drainage and water saturation conditions. Forest masses of the middle-taiga (spruce-fir-cedar and pine-birch) type, southern-taiga type (spruce-cedar-fir), and birch-pine forests are developed on the drained slopes. There are deposits of oil and gas (Ust’-Balyk, Pravdin, Myl’dzhin, and Ust’- Sil’gin).