a mountainous region in the Yakut ASSR bounded by the Verkhoiansk and Suntar-Khaiata ranges on the southwest and the Cherskii Range on the northeast.
The Iana-Oimiakon Highland is about 1,100 km long and consists of variously oriented ranges (Tirekhtiakh, Nel’gese) alternating with broad high plateaus (lana, Oimiakon, El’gi) and in-termontane depressions. It has elevations of 500 to 700 m in the basin of the middle lana and 1,400 to 1,500 m in the southeast. Individual peaks reach an elevation of 2,000 m. The highland is composed of Triassic and Jurassic aleurolites, sandstones, and shales, which are severely dislocated and intruded by granite. Low, thin larch taiga occurs in the valleys and on the slopes; steppe vegetation is encountered in some areas on south-facing slopes. Mountain tundra is found in the upper belt.