The calculated distance (air line) between Baruun-Urt and Undurkhaan is approximately 131 miles respectively 211 kilometers.
By car or train, the actual journey to Undurkhaan is certainly longer, as only the direct route (as the crow flies) between Baruun-Urt and Undurkhaan has been calculated here.
Air line (approximately)
211 kilometers
114 nautical miles