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