The calculated distance (air line) between Semonkong and Mohale's Hoek is approximately 40 miles respectively 65 kilometers.
By car or train, the actual journey to Mohale's Hoek is certainly longer, as only the direct route (as the crow flies) between Semonkong and Mohale's Hoek has been calculated here.
Air line (approximately)
65 kilometers
35 nautical miles