The calculated distance (air line) between Omsk and Nizhnyaya Omka is approximately 69 miles respectively 111 kilometers.
By car or train, the actual journey to Nizhnyaya Omka is certainly longer, as only the direct route (as the crow flies) between Omsk and Nizhnyaya Omka has been calculated here.
Air line (approximately)
111 kilometers
60 nautical miles