In June 2020, a field team from Mongolian Bird Conservation Center was carrying out survey of feasibility study on World heritage nomination for Eastern Mongolian Steppes in Matad soum, Dornod province, in the Southeastern part of Mongolia. On 12 June 2020, the team walked along the canopy of Elm tree Ulmus pumila in Yondon’s Elm Tree valley (47.217846°N 115.787143°E) for birding (Plate 1). During this walk, we noted a mysterious chestnut colored thrush with yellow bill flying in between trees and rocks but we couldn’t identify, because it was very shy. We discussed and decided to walk again in the valley to take better shots, and this time noted again and obtained some images of the species (Plate 2). At first we identified it as breeding Pale Thrush Turdus pallidus which is still rare visitor for the country (Gombobaatar and Monks, 2011), and we checked the books we had, but we could not find this thrush from the guide book of Birds of East Asia and Birds of Europe. We believed it might not be a Pale Thrush based on its colorful plumage, instead it could be a new species in Mongolia. Once online again, using various web sources we identified it as Chestnut Thrush Turdus Rubrocanus, a first record for Mongolia.