By car: on the A41 motorway, take exit 24.1 and follow signs for Villard-Bonnot via the D165, then turn left onto the D523. In Villard-Bonnot, at the traffic lights, turn right towards Saint-Mury-Monteymond via the D165. In Saint-Mury-Monteymond, leave the village on your right and continue straight ahead on the D280. At the entrance to the hamlet of La Gorge, cross the bridge at a bend and, before the second left-hand bend, turn right onto the Chemin des Cascades, which follows the Ruisseau de Vorz. After about 500 m, there is an unpaved hump which you must drive over at walking pace, especially when going downhill, as you risk scraping the underside of the vehicle. Cross the stream at a hairpin bend and stop 100 m further on, near the hiking sign.
(S/E) At the ‘Le Chenevrey’ sign (alt. 910 m), head south towards Le Pleynet / Refuge Jean Collet along a track and then a path through the woods, marked in yellow, which shortly afterwards turns south-east and runs along the Ruisseau de Vorz on the upper bank. Pass a high point before descending via a slightly steep section, secured by a cable, and reach the bank of the stream, which is strewn with boulders.
(1) As you pass, note a footbridge spanning the stream opposite. Five metres further on, head back up the path and continue straight ahead, ignoring the fork to the left towards the footbridge. Leave the forest behind to cross a field of tall wild grasses, where a superb view opens up over the veiled waterfalls cascading down the eastern cliff face and, at the back of the cirque, the tumultuous waterfall of the Ruisseau de Vorz. Keep to the right as you climb through the forest via switchbacks on the right-hand side of the valley and reach the junction with the Pré Long / Pré Comté path.
(2) At the ‘Le Pleney’ sign (alt. 1,480 m), follow the sign for Passerelle du Mousset / Refuge Jean Collet to the left (south-east). As the forest thins out, cross a scree slope then climb in a zigzag pattern up the slope to reach a virtually level grassy area. Cross the Ruisseau de Vorz via a footbridge and arrive at a fork in the path.
(3) At the ‘Passerelle du Mousset’ signpost, leave the marked path to the left (north) towards the Refuge Jean Collet. Turn right (south) onto an unmarked track running alongside the stream. After about thirty metres, you’ll come to a large cairn. Ignore the track continuing along the stream and turn left (east) onto a well-marked path. Winding your way up in a series of hairpin bends (south-east) up the steep slope on the left-hand side of the valley, you’ll reach a path (alt. 1900 m).
(4) This path, marked in yellow, links the Jean Collet refuge to Lac Blanc. Ignore its left-hand branch (north), marked by a small ‘Jean Collet’ sign fixed to the rock face. Continue straight on (south) across the scree. Cross a small stream via a hairpin bend over slippery rock slabs. As the slope becomes steeper, the path makes two wide hairpin bends before turning north-east, skirting the rock face. Turn right (south) to climb up a series of steps. After a slight flat section, the path climbs more gently towards the east.
(5) At the top, a superb panorama unfolds, with Lac Blanc—with its astonishingly milky-blue waters—some twenty metres below. The lake is surrounded by peaks still snow-capped at the end of the season, including the Grand Pic de Belledonne, which rises to 2,978 m, with the meagre Freydane glacier still lingering at its foot. Continue along the unmarked path overlooking the lake. At the end of the path, ignore the path leading down to the right towards the eastern shore and carry on straight ahead until you reach a stream feeding into the lake.
(6) Ignore the path to the left (north-east) which climbs alongside the torrent towards the Col de Roche Noire. Head south-east, towards the moraine in the direction of the Grand Pic de Belledonne.
(7) At the fork (alt. approx. 2,250 m), leave the Col de Freydane path on the right (south), which crosses the lake’s main tributary. Continue left over the scree, heading for the Grand Pic de Belledonne and the base of the glacier, on a path running along the moraine between its crest and this glacial outlet stream. At around 2,400 m, as the slope becomes steeper and you approach a rocky outcrop on the right, go round it via a wide right-hand bend which leads to the foot of the Freydane Glacier and its small catchment lake (alt. 2,450 m).
(8) The return to the car park (S/E) follows the same route as the outward journey.