Tsetserleg city is located in the eastern part of Hangai dome. During the winter, the city is heavily affected by air pollution due to the burning of coal. Using geothermal resources in the region, manifested by the presence of hot springs in the region, could dramatically reduce air pollution. To understand the nature of the geothermal reservoir feeding the hot springs, we conducted magnetotelluric surveys in the Tsenkher hot spring region south of Tsetserleg in 2019 and 2020. To obtain a subsurface electrical conductivity model of the hot spring area with magnetotellurics (MT), we inverted data collected in 2019 and 2020 at 126 MT sites, from a total of 306 sites, obtained in the Tsenkher geothermal area. For 3-D modelling and inversion of the MT data we used the high order finite element code GoFEM (Grayver, 2015). Locally refined unstructured meshes are used to ensure numerical accuracy with a sufficiently fine discretization of the inversion domain, while keeping the computational cost feasible. To recover a 3-D electrical conductivity model, we invert the full impedance tensor rotated into geoelectric strike direction. The best fitting model provides important new insights into the subsurface structure of the Tsenkher geothermal region. The model is characterized by a prominent crustal conductor that appears under the hot spring areas and rises from depths of more than 10 km to the surface. We interpret the conductor as being related to local volcanism and as a zone rich in partial melt and magma-derived fluids, serving as the heat source feeding the hot springs.