Geez, that finish is going to be dicey for the leaders, and especially the peloton! Can't imagine going down hills like that in a group of ~150 riders...
From the Sentinelle's summit, the narrow, twisty back road descends through 600 vertical feet in 5km, then goes up a short hill before descending another 300 feet in 1.5km. This brings the course within 2km of the finish - which races through the streets of Gap via five roundabouts to a short, 300-meter-long finishing straight.