The calculated distance (air line) between Ulan-Ude and Gusinoozyorsk is approximately 61 miles respectively 98 kilometers.
By car or train, the actual journey to Gusinoozyorsk is certainly longer, as only the direct route (as the crow flies) between Ulan-Ude and Gusinoozyorsk has been calculated here.
Air line (approximately)
98 kilometers
53 nautical miles