When driving up to Chamrousse, park in a large car park accessible from a hairpin bend in the road. This car park is just below the start of the Casserousse chairlift.
(S/E) Take the yellow-marked path which climbs due south. It is a route through the forest, mostly along a stream. Reach a junction.
(1) Ignore the signs for Le Recoin and the Col de la Balme and head left towards Lac des Pourettes, which you’ll reach after a long traverse through the undergrowth.
(2) Go past the lake on the right and begin a steep climb through a field of boulders. After the northern gap, descend towards the eastern shore of the large lake.
(3) Turn right between the lakes, pass a shelter and reach a junction near the start of a chairlift.
(4) Turn left onto the path that climbs to the Col des Lessines.
(5) Turn right onto the path which continues to climb and reach the Col de la Botte.
(6) Continue to the right along a track towards the Col des Trois Fontaines and the Croix de Chamrousse, a little further up where the top station of the Croix de Chamrousse gondola lift is located.
(7) Head west for a descent via the black ski run (this is the start of the men’s Olympic downhill run) then via the red run, which was the women’s course. There is no clearly marked path, just the occasional random tracks. In fact, you should aim for the Col de la Balme, with a small hillock in the background. Reach this pass.
(8) Head down northwards along a ski run to reach, a little further down, the junction of the circular route you passed earlier.
(1) Finish the descent via the path taken on the ascent to return to the Casserousse car park (S/E).