The "Razrez Tugnuyskiy" is one of the largest coal mining enterprises in Russia. It carries out open-cast mining of the Olon-Shibirsky coal field located in the Petrovsk-Zabaikalsky District of the Trans-Baikal Territory and in the Mukhorshibirsky District of Buryatia.The central part of the deposit is located 90 km southeast of the city of Ulan-Ude. The deposit is represented by 21 coal seams, of which four are of industrial importance - № 6, 8, 15, 18.The main working seamis seam№ 18 (64% of all reserves). Depth of its occurrence - from 3 to 169 meters. According to the data of geological prospecting, the coal reserves at the Tugnui section today make up 230 million tons.