Lac Blanc, at 2352m, is one of the most famous walks in the Alps – hugely popular for its straightforward access to a spectacular panorama over the Mont Blanc massif, and especially for the stunning reflection in the lake.
It really is an amazing view – the peaks frame the lake and surrounding landscape perfectly, and on a still day, the reflection is incredibly dramatic.
There is often snow around at the lake in summer, though increasingly in hotter years there is less. Poles are very useful, especially if there’s any snow around – I don’t personally do this walk without poles and boots with good ankle support: it is rough and stony, and easy to slip on loose rock on the descent. Allow an absolute minimum of 4-5 hours for the walk, including time to explore around the lake and take photos.
You may well see ibex and marmots along the way! It’s in the nature reserve, so dogs are not allowed, and neither is swimming – it’s glacially cold anyway, but more importantly has a very fragile ecology.
Lac Blanc plus points
– Often has snow until later summer for a lovely high mountain atmosphere
– Amazing and highly photogenic panorama reflected in the lake.
– Beautiful views along the path
– Can be good for less experienced walkers, older people and families. It doesn’t have much of the precipitous drops of many trails, the “out and back” route is not committing, and the path from Flegere is very straightforward walking and well signed.
But
– Not a place to go for Alpine peace. Can be extremely crowded including large tour groups and school groups. – Much of the path is stony, it’s not the most pleasant walking.
– You’re in the ski area for much of the first part which is a bit scarred
– Beautiful but rather harsh environment, especially on the higher route from the Index, not many flowers and few trees
– At considerable altitude: most people will feel some shortness of breath
My personal view
If I had time for one or two walks only, this might not be one of them. It really can be very crowded. I think both the Balcons (Nord and Sud) are prettier and have nicer trails, with essentially the same views. For high rocky alpine beauty I prefer Lac Noir. But this is being very picky! It’s got to be in the top ten, and if you get there early it’s a magic spot. You can go via Lac Cheserys (below) which has similar views and is usually less of a circus.
Routes
It’s usually begun in one of three places:
- The Index lift at the top of Flegere (2525m)
- The Flegere midstation (1913m)
- Tré-le-Champ just above Argentiere (1417m)
At first glance, it seems clear that it would be better to go from Index (2525m), the highest point accessed by a lift. However, it’s worth noting that this is a more technical trail to walk on, with some areas of loose scree with a lot of up and down along the way. Experienced walkers should have no trouble but it’s not necessarily the easy option it appears at first glance, and may not be suitable for small children or the less fit.
It also can be inaccessible even in summer, as it’s around the same height as the lake and can have dangerous hard packed snow (névé) in the couloirs.
If you walk from the Flégère mid station (1913m), it’s a straightforward walk on a fairly easy trail but with a climb of around 500m.
The boardwalks fitted in recent years around the small lakes on the way have been a big improvement and are a nice destination in themselves.
You can either walk directly there or via Lac Cheserys, which is rather longer but also slightly easier, on a wide track for part of the way. Lac Cheserys is itself a very beautiful spot.
Going from the top of the Index lift to the Lac Blanc, and then walking down to Flegere mid station via Lac Cheserys on the way back makes it into a nice loop and is perhaps the ideal solution if the Index path is OK for you.
To go from Tré-le-Champ makes it into a beautiful full day for those who’d like more of a challenge.
Walk through a lovely open larch forest which is good place to see wildlife, and then take one of two variants. Either via the Aiguillette d’Argentiere, which takes you past a spectacular climbing crag, or the easier route via Chalets des Cheserys. NB There are laddered sections on the Aiguillette variant, it is recommended for experienced and fit walkers only. Here’s my separate page covering this walk.
When to go
Time
It’s really so much better to do it first thing in the morning. Once you’re above the mid station it’s a true high alpine environment with little shade or greenery, and the heat can be fierce. It also gets very busy, especially at weekends – well worth getting up early for some peace and quiet! Also, it’s not great to be hurrying back to get the last Flegere lift down, and even worse if you miss it and have to walk down! I like to do first lift for Lac Blanc or 9 am at the latest. If going via Tre-Le Champ there is a lot to be said for an even earlier start.
Season
It’s usually full winter conditions there until mid-June at the earliest.
These photos are from the end of June, as you can see conditions are extremely marginal, with very little of the lake visible. The top route from the Index was too dangerous to use.
As you can see (above), there was very little of the lake thawed out ! With a lot of contortion I did manage to get the panorama pic in the end (below)
July, August and (especially) September are the best times to go. However, snow levels and ease of access varies wildly from year to year. Sometimes you can get there in mid June, sometimes it remains difficult well into July. It’s best to check with the staff at the lift station or the Office du Haute Montagne and ask which route they recommend.
Autumn
Sometimes the Flegere lift runs in October or November for the Toussaint holidays, and Lac Blanc may be accessible – this is an excellent time to go. And of course you can walk up from Tre-le-Champ at any time, in theory. However, conditions vary yearly and daily! Always check with the Office du Haute Montagne as it is a very dangerous place in bad weather.
Winter
In winter (generally late November to mid-June at this altitude) it is a completely different prospect: there is no signposting and it can be only accessed with a guide, via ski touring or (sometimes) snowshoeing. Since the lake is invisible under the snow, it loses much of its impact anyway. If you want to see almost the same view in winter, away from the lifts, I highly recommend the Flegere inbounds snowshoeing trail which is very well planned and signposted.
Ski Touring access with a guide
If you like to ski tour (or want to try it) with a guide it is a lovely ski tour, with the option to continue up to the Col De Belvedere. It’s an excellent place for a first ski touring experience. In 2026 the refuge opened for the first time in spring for ski touring, and we very much hope this becomes a fixture, as having the refuge open lends a wonderful atmosphere as well as logistical advantages and a great lunch stop. It is much (much!!!) less busy in winter.
Food
There is a pleasant refuge at the lake where you can get drinks, snacks and simple lunches. It is very busy in summer (though in winter it is lovely). By far the nicest thing to do in summer, I think, is to take sandwiches and find a quiet spot away from the crowds – you don’t generally have to go far. If you do want to eat there in summer, it may be vital to reserve in advance, and you don’t want to be in any hurry.
Kids
Although Lac Blanc is widely advised as suitable for absolutely everyone, this has always surprised me. It’s a big, hot, committing walk with quite a lot of ascent at considerable altitude and my personal opinion is that it needs caution with kids. I would recommend trying some easier walks first, and allowing lots of time. The lakes by the boardwalks make a nice destination – you are about a third of the way there at this point so you can judge how everyone is going. Do note that you should not swim in these lakes either due to their delicate ecology. Sunscreens etc have a particularly bad effect on them.
Linked walks
If you are fit, it is completely feasible to link it with other walks and I highly recommend this.
– Ascend or descend from Tre-le-champ (or the nearby Col des Montets) beautiful and a great sense of achievement but you need to be fit and experienced, it’s quite technical with two ladder sections.
– Combine with the Grand Balcon Sud, finishing at Brevent for an amazing Mont Blanc view. Probably my favourite option. A big day, but very doable, and you can always bail at Flegere if you like.
– Could be combined with Col des Glieres & Lac Noir for an in-depth traverse of the south side. To do this would be a very big day, though it is certainly possible for a fast walker or trail runner. It wouldn’t allow much time for photo taking or just absorbing the view, however. Of course, it’s relatively straightforward to split it up via the cable car stops and take as long as you like!
Access from La Petite Forêt
The Flegere lift is a five to ten minute walk from the chalet, so you can start directly from the door…
or more importantly, return directly to the hot tub!
If you want to do the bigger walk from Tre-le-Champ, there’s plenty of parking.
You can get there by public transport which is also useful if you want to take a different route back. To go direct to Tre-le-Champ, you need to take two buses – several routes from from Flegere to Argentiere, and then the No. 21 to Tre-Le-Champ. It is probably easier to take the more frequent bus or train to Montroc Le Planet – Tre-le-Champ is about 15 minutes walk from there.
A note on safety & maps
These walks are all ones that I’ve enjoyed myself, and they are here to help you with inspiration and planning. It’s not intended to be a full guide to each walk and I really recommend a book such as Mont Blanc Walks: 50 best walks and 4 short treks (Cicerone Guides) or Mont Blanc Trails (with accompanying map). If you’re staying with us, we have copies which you are welcome to borrow. If not, they are easily available from bookshops in Chamonix. The tourist office does a little map for a few euros which would be more than enough for Lac Blanc.
These are summer walks only – and conditions vary enormously throughout the summer. Please read my accompanying post on walking safety, and happy trails!
