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