The calculated distance (air line) between Saint-Louis du Nord and Cap-Haïtien is approximately 36 miles respectively 58 kilometers.
By car or train, the actual journey to Cap-Haïtien is certainly longer, as only the direct route (as the crow flies) between Saint-Louis du Nord and Cap-Haïtien has been calculated here.
Air line (approximately)
58 kilometers
31 nautical miles