The Eastern Sayan extends 1000 km from the Yenisey River at 92° E to the southwest end of Lake Baikal at 106° E. The Western Sayan forms the eastern continuation of the Altay Mountains, stretching for 500 km from 89° E to the middle of the Eastern Sayan at 96° E.
The Sayan Mountains' towering peaks and cool lakes southwest of Tuva give rise to the tributaries that merge to become one of Siberia's major rivers, the Yenisei River, which flows north over 2000 miles to the Arctic Ocean. This is a protected and isolated area, having been kept closed by the Soviet Union since 1944.
While the general elevation is 2000 to 2700 m, some of the individual peaks, consisting largely of granites and metamorphic slates reach altitudes of over 3000 m, with the highest being Munku-Sardyk at 3492 m. The principal mountain passes lie 1800 to 2300 m above the sea, for example Muztagh pass at 2280 m, Mongol pass at 1980 m, Tenghyz pass at 2280 m and Obo-sarym pass at 1860 m.
At 92°E the system (the Western Sayan) is pierced by the Ulug-Khem (Улуг-Хем) or Upper Yenisei River, and at 106°, at its eastern extremity, it terminates above the depression of the Selenga-Orkhon Valley. From the Mongolian plateau the ascent is on the whole gentle, but from the plains of Siberia it is much steeper, despite the fact that the range is masked by a broad belt of subsidiary ranges of an Alpine character, e.g. the Usinsk, Oya, Tunka, Kitoi and Belaya ranges.
Between the breach of the Yenisei and Lake Khövsgöl at 100° 30' E. the system bears also the name of Yerghik-taiga. The flora is on the whole poor, although the higher regions carry good forests of larch, pine, juniper, birch, and alder, with rhododendrons and species of Berberis and Ribes. Lichens and mosses clothe many of the boulders that are scattered over the upper slopes.