|Time zone||UTC + 8 (UTC+8)|
Tsagaan-Uul (Mongolian: Цагаан-Уул, lit. "white mountain") is a sum of Khövsgöl aimag. The area is about 5,870 km², of which 5,190 km² are pasture. In 2005, the sum had 5145 inhabitants, mainly Khalkha and Khotgoid. The center officially named Sharga (Mongolian: Шарга), is located 138 km west of Mörön and 840 kilometers from Ulaanbaatar.
The Tsagaan-Uul sum was founded, together with the whole Khövsgöl aimag, in 1931. In 1933, it had about 3,800 inhabitants in 1150 households, and about 101,000 heads of livestock. in 1959, parts of Tsagaan-Uul were carved out to form Bürenkhaan sum, in 1963 Sharga sum was joined to Tsagaan-Uul, and in 1973 Bürenkhaan sum was dissolved again and partially joined to Tsagaan-Uul. The local negdel, under the name Badral, was founded in 1956.
M.Nyamaa, Khövsgöl aimgiin lavlakh toli, Ulaanbaatar 2001, p. 192f