Tour du Mont Blanc

The whole day's climbing is done in the first two hours. From Les Houches the route goes straight up on village lanes and then wide ski-area track, about 650 m to Col de Voza at 1653 m, where the rack line of the Tramway du Mont-Blanc is crossed. None of it is technical and none of it is interesting underfoot: hard, broad, mostly shadeless. Past the col the character changes completely, into a descending path through birch and spruce above the Bionnassay torrent, past the hamlet of Bionnassay and down to the floor of the Montjoie valley. From there to the end of the section it is low, undulating walking on forest tracks, farm lanes and short stretches of tarmac, threading hamlet after hamlet. It never settles into a rhythm and it is the least alpine ground on the circuit, but it is also the most populated, so nothing is far away. The section stops on the wooded rise just short of Les Contamines.

Logistics: The Bellevue cable car out of Les Houches removes the Col de Voza climb, which is why a lot of walkers arrive at Bionnassay with fresh legs and a very different day behind them.

Navigation: Red and white GR blazes throughout and the line is obvious, but the pistes and service tracks around Le Prarion and Col de Voza cross each other repeatedly and the wrong track down is easy to take. The Col de Tricot variant leaves at the col: it is higher, steeper and longer, not a short cut.

The one genuinely easy stretch on the French side. The trail runs through Les Contamines-Montjoie on pavement, then follows the Bon Nant upstream on flat gravel tracks and easy forest path to the baroque chapel at Notre-Dame de la Gorge, gaining barely 150 m in six kilometres. Shaded, level, and shared with day walkers, families and the leisure park at Le Pontet, so it is sociable rather than wild. It ends where the tarmac does. Everything past the chapel is climbing.

Navigation: Signed and unmistakable, on tarmac and broad gravel track the whole way up the valley.

The heart of the walk and the part that has to be respected: two frontier cols, 44 km and most of the circuit's serious ground. It opens on the Chemin Romain above Notre-Dame de la Gorge, a steep paved and slabbed climb through the gorge that is slick when wet, then eases onto pasture track past Nant Borrant and La Balme before the treeline is left behind for good. Above that it is open, stony ground to Col du Bonhomme at 2329 m and a further exposed traverse to the Croix du Bonhomme at about 2480 m, the highest point on the French side and where snow lies longest. The drop to Les Chapieux is grassy, long and hard on the legs. Tarmac up the Vallée des Glaciers gives an easy start to Col de la Seigne, a broad gradual climb with false summits that finishes on the Italian border. Past it the country changes: Val Veny is wide, bare and glacier-scoured, the path following the Miage moraine to Lac Combal before a strenuous pull onto the Mont Favre spur at around 2430 m. That buys several kilometres of near-level balcony traverse facing the Peuterey ridge and the Italian side of Mont Blanc, which is as good as walking gets on this circuit. It ends badly, on steep, loose, dusty ski pistes from Col Chécrouit down through Plan Chécrouit to Dolonne and Courmayeur.

Logistics: There is no road between Notre-Dame de la Gorge and Les Chapieux, about 15 km over two cols, and none again beyond Refuge des Mottets until the Val Veny road head at Lac Combal. From Notre-Dame de la Gorge to the Col du Bonhomme the route is inside the Réserve naturelle nationale des Contamines-Montjoie, roughly km 20.5 to km 30 on the line stored here. Under a prefectural order of 4 June 2026 bivouac is prohibited in that reserve from 15 June to 15 September except on the designated ground at Pont de la Rollaz and at La Balme, where the pitch has to be booked in advance, on reserve-bivouac74.fr, and is only usable between 19:00 and 09:00. Sleeping out on this climb is a thing you book before you start walking, not a thing you decide at six in the evening. Sheep are grazed on the same ground with livestock guardian dogs. The commune of Les Contamines names Plan Jovet, between La Balme and Lac Jovet, and the ground near the Col du Bonhomme; the route runs straight through Plan Jovet at about km 26 and over the col ground between roughly km 28.5 and km 30.5, so both are on the line rather than beside it. The third sector the commune names, between Veleray and the Aiguille Croche on the slopes of the Tête de la Combaz, is about 4 km off the mapped line and only concerns walkers taking the Aiguille Croche variant. The commune's own advice is to slow down and let the dog hear you, go round the flock as widely as the ground allows, and if a dog comes to you stand still facing it with your arms and poles down at your sides, do not look it in the eye, speak calmly, then walk on slowly.

Navigation: Waymarking is good, but above the treeline the ground hides it. The traverse between Col du Bonhomme and Col de la Croix du Bonhomme is where care is needed: it is exposed, the underlying path is covered when snow lies, and the descent line off the Croix towards Les Chapieux is the classic place to lose it in cloud. The Col des Fours variant, higher again, leaves at the Croix du Bonhomme. Below Col de la Seigne the paths through the upper Val Veny braid and rejoin, which looks like a navigation problem and is not.

Two balconies and a border. From Courmayeur the trail climbs about 800 m through larch woods above Villair to Rifugio Bertone, a sustained forest pull with the treeline only at the top and a single viewpoint back over the town for relief. What follows is the easiest hard walking on the tour: a near-level traverse along the flank of Mont de la Saxe, high above the Val Ferret road, with the Grandes Jorasses filling the view opposite. It is open grass and stone with no shade and no shelter between Bertone and Rifugio Bonatti. The balcony runs out at the head of the valley at Arnouvaz, then a steady zigzag climb past Rifugio Elena on grassy hillside reaches the Grand Col Ferret at 2537 m, the trail's high point and the Swiss frontier. The Swiss side is gentler at once: pasture, the alp buildings at La Peule, then a long descent on tracks and lanes through Ferret into La Fouly. From there to Praz-de-Fort the walking is riverside and almost flat, wooden chalets and hay meadows, the quietest and least strenuous ground on the whole loop.

Navigation: Mostly simple: the balcony is a single obvious line and Swiss signposting on the far side is the clearest on the circuit. Two things to know. The Col Sapin and Tête de la Tronche variant leaves at Rifugio Bertone and is a fair-weather route rather than an alternative. In the Swiss Val Ferret the path between Prayon and Branche, at Treutsebo, has been rerouted onto the right bank of the Dranse de Ferret because of rockfall and the old line is closed, so follow the marking on the ground rather than an older track log.

Swiss forest and pasture, then back over the frontier and straight into the Aiguilles Rouges. A steady wooded climb from Issert to the lake at Champex ends the valley walking. Outside Champex the route forks, and the mapped line takes the Bovine route: a farm road to Plan de l'Au, then a steep, rooty, stream-crossed 45 minutes through the woods and about 650 m of climbing to the working alp at Bovine, where the cattle churn the ground and the view opens north to Martigny and the Rhône. It is not a col but it climbs like one. The descent to Col de la Forclaz through fields and woodland is gentle and quick. From Trient the section starts again from nothing: gravel track across meadow, then forty minutes of tight forest switchbacks and open hillside to Col de Balme at 2191 m, where the Chamonix valley and the whole north side of Mont Blanc appear at once. The mapped line then takes the crest of the Aiguillette des Posettes, rocky, narrow, increasingly uneven and completely exposed, before dropping in switchbacks to the valley road at Tré-le-Champ. The last kilometre climbs straight back out of the valley to the fixed ladders on the Aiguillette d'Argentière, a protected passage of metal ladders, handrails, platforms and steps broken by stretches of ordinary path. The route stays high above Argentière and does not enter it.

Logistics: The Fenêtre d'Arpette variant at 2665 m is a different route rather than a scenic option: a boulder field with hands-on scrambling, an extremely steep final pull and a steep, tricky descent past the Trient glacier moraine. It is a settled-weather choice, made in Champex before the fork. The end of this section enters the Réserve naturelle nationale des Aiguilles Rouges. On the boundary as mapped in OpenStreetMap the stored line touches the reserve near the Col des Montets at about km 140, leaves it, and is back inside it from the foot of the ladders at about km 144 onwards. Dogs are not allowed in the reserve at all, so a walker with a dog has to solve that before leaving home rather than at Tré-le-Champ. Camping is prohibited and a bivouac needs a pitch booked in advance on reserve-bivouac74.fr under the prefectural order of 4 June 2026, tolerated only between 19:00 and 09:00. Swimming is prohibited in Lac Blanc and the Lacs des Chéserys, which is the detour most walkers make from the Tête aux Vents junction at the start of the next section.

Navigation: Swiss signposting is the clearest and most comprehensive on the circuit, with walking times as well as directions. The fork that matters is just outside Champex, where the Fenêtre d'Arpette variant goes west up the Val d'Arpette and the main Bovine line goes southwest towards Champex d'en Bas; make that choice in the village, not at the sign. At Col de Balme the mapped crest route over the Aiguillette des Posettes separates from the older, lower path down to Le Tour. On the descent off the Posettes the crest gives out into several junctions below the treeline, all signed for Tré-le-Champ. Walkers who do not want the ladders leave the line at Tré-le-Champ for the Col des Montets variant.

The Grand Balcon Sud, and the best sustained viewpoint on the circuit. From the cairn at La Tête aux Vents the path traverses southwest across the Aiguilles Rouges reserve at around 2000 m, dropping to the lift station at La Flégère and then rising and falling over rocky meadow, scree and boulder to Planpraz. It is stony the whole way, with ramps and stone steps where the ground steepens, and it walks slower than its modest height gain suggests. The slope faces south, straight across at the Chamonix Aiguilles and the Mont Blanc massif, which is the entire reason for being here. The trail stays high on the valley wall and does not go down into Chamonix or Les Praz, though lifts at both ends do. Expect company: this is a lift-served day walk as much as a stage of the TMB, and one of the better places on the route to see ibex and chamois.

Logistics: The traverse starts inside the Réserve naturelle nationale des Aiguilles Rouges. On the boundary as mapped in OpenStreetMap the stored line is in the reserve from the Tête aux Vents cairn to about km 147.5, in the basin above La Flégère, and the developed lift ground at La Flégère and Planpraz sits outside it. Dogs are forbidden in the reserve outright, not merely required to be on a lead, and a bivouac needs a pitch booked in advance on reserve-bivouac74.fr. Both matter here because the lifts at either end make this the easiest stage on the circuit to arrive on with a dog or a tent.

Navigation: The junction at La Tête aux Vents, marked by a large cairn, is the one to get right: the path north climbs to the Lacs des Chéserys and Lac Blanc, the TMB turns southwest for La Flégère. After that the balcony is a single line across the hillside with a lift station at each end, and it is hard to lose.

A last climb, then the biggest single descent on the circuit. The pull from Planpraz to Le Brévent at 2525 m finishes across a boulder field crossed on laid rock slabs. From the summit, with the whole massif directly opposite, the trail drops past Lac du Brévent to the Refuge de Bellachat and then falls roughly 1200 m down the flank of the Aiguillette du Brévent. That descent is the section: loose stone on steep ground, timber-reinforced steps, fixed metal handrails where the path is cut through rock, and one crossing of the Ravin des Vouillourds secured with a chain. It is continuous rather than technical, and it is quads and knees that pay for it. Below the Merlet junction the trail enters forest, skirts the Parc de Merlet and joins a paved access road, then drops on lanes and woodland path into Les Houches to close the loop. It stays on the west wall of the valley throughout and does not pass through Les Bossons.

Logistics: The Brévent cable car at the summit is the last opportunity to hand the 1500 m descent to a machine, and the only one. Le Brévent and the top of the descent are back inside the Réserve naturelle nationale des Aiguilles Rouges: on the boundary as mapped in OpenStreetMap the stored line is inside it from about km 155.3 to km 158.9, which covers the summit, Lac du Brévent and the ground down to just above the Refuge de Bellachat. The outright dog ban and the booked-pitch bivouac rule apply on all of it. The bivouac ground beside the Refuge de Bellachat at km 159.1 falls a little below the mapped boundary, so ask the refuge which rule you are under before counting on a night there to break the 1200 m descent.

Navigation: One obvious line from Planpraz over Le Brévent and down. Signs at Bellachat give Merlet and Les Houches, and the route follows the perimeter of the Parc de Merlet before joining its access road; below that there are several ways into the village and all of them work.