The calculated distance (air line) between Sainte-Marthe-sur-le-Lac and Gatineau is approximately 86 miles respectively 138 kilometers.
By car or train, the actual journey to Gatineau is certainly longer, as only the direct route (as the crow flies) between Sainte-Marthe-sur-le-Lac and Gatineau has been calculated here.
Air line (approximately)
138 kilometers
74 nautical miles