Rue mount extension as currently shown does not exist. This is, in fact the old hydro line path. 

The actual Rue Mount extension (which will soon be renamed to avoid confusion with the actual Rue Mount that is correctly shown on the map, and which does NOT connect to the extension) begins at the end of Ch. du Lac Thurson. 

The path of the actual Rue mount extension including the finalized rue Thurson which extends  and intersects with the Orphelin trail, can be seen using the Strava Heat Map as well as certain other updated map services (Google maps). 