The ecoregion spans roughly 1,000 km, from the Khan-Khokhi mountains in the Baruunturuun district of western Mongolia, to Ulan-Ude, the capital city of Buryatia in Russia, just east of Lake Baikal. Along the way it passes through the drainage basin of the upper Selenge River and its tributaries, the valley of the Orkhon River, and along the Selenge River Valley into Russia. In the middle, the ecoregion wraps around the higher forested area of the Khangai Mountains. The mean altitude of the area is 800-1200 meters, with peaks ranging up to 2900 meters.