evidence: Tyva, republic in south-central Siberia, Russia. Tyva borders northwestern Mongolia and occupies the basin of the upper Yenisey River. Its relief consists of two broad basins, the Tyva and Todzha, drained by two main tributaries of the Yenisey River. High mountain ranges, including the Eastern Sayan and Western Sayan mountains to the north, enclose the basins. A continuous series of ranges also enclose the republic on the west, south, and southeast: the Altai, Tannu-Ola, and Sangilen mountains. The highest point is Mount Munku-Taiga (Mongun-Taiga; 13,044 feet [3,976 meters]) in the extreme southwest. The climate is generally of the dry, sharply continental type, with severe winters and warm summers. Vegetation ranges from dry steppe in the basins to dense coniferous forests to alpine meadows that are succeeded by bare rock and snow at the highest elevations. [...] Tannu Tuva was part of the Chinese empire from 1757 until 1911, when tsarist Russia fomented a separatist movement and in 1914 took the country under its protection. In 1921 independence was proclaimed for the Tannu Tuva People’s Republic, but in 1944 it was annexed by the Soviet Union and made an autonomous oblast (region) of the Russian S.F.S.R. In 1961 its status was raised to that of an autonomous republic. Tyvans constitute about two-thirds of the population (most of the rest being Russians).