Missed the turn to the top of the ski lifts at the col de Marcieu. Instead took an interesting looking trail that climbed steeply but had a good surface. This track is not shown on the IGN map but on the local "plan cadastral". I didn't take it to the summit where it would have led to the top of the ski runs. Could be a good alternative route with slightly less climbing, km, see GPS route.
Weather: Warm, fine.
Country: France Area: Chartreuse Trailhead: St Hilaire du Touvet