The calculated distance (air line) between Tuyên Quang and Bắc Kạn is approximately 46 miles respectively 73 kilometers.
By car or train, the actual journey to Bắc Kạn is certainly longer, as only the direct route (as the crow flies) between Tuyên Quang and Bắc Kạn has been calculated here.
Air line (approximately)
73 kilometers
40 nautical miles