The calculated distance (air line) between Roches Noire and Chemin Grenier is approximately 31 miles respectively 49 kilometers.
By car or train, the actual journey to Chemin Grenier is certainly longer, as only the direct route (as the crow flies) between Roches Noire and Chemin Grenier has been calculated here.
Air line (approximately)
49 kilometers
26 nautical miles