Section 6 of the Trans-European Alpine Route
The Pyrenees form the natural border between France and Spain and are certainly one of the highlights of the TEAR. Hiking through the Pyrenees is just as beautiful and arduous as in the Alps, perhaps even more so. They are also less busy, which will be magnified by the shoulder season timing in which you'll likely be hiking. You'll have most of the trails to yourself.
The 'nuts and bolts' of the section are provided in the map above, which can be exported for use in offline GPS apps. Information is divided into subfolders for easier viewing and additional details/context are given below.
There are three well known routes which traverse the Pyrenees - the GR10 (stays in France), the GR11 (stays in Spain), and the Haut Route Pyrenees (HRP). The HRP is a high route which zig-zags across the Spain/France border while following a combination paths including parts of the GR10 and GR11. While there are official or traditional routes for the HRP to be found online, it is more of a concept for a high crossing of the Pyrenees and there are many possible variations. The main trail for the TEAR continues briefly on the GR36 until joining the Haut Route Pyrenees (HRP) which it follows for the rest of the traverse. While I've chosen to follow the HRP, others might hike the GR10 or GR11 due to visa considerations or simply as a preference. There is a great comparison of all three routes here. There are guidebook available for the GR10, GR11, and gpx tracks for each can be found online. There is also a guidebook for the HRP, as well as an excellent free online guide with downloadable gpx tracks and variations.
There is plenty of room for variation through the Pyrenees, and I've included all of the relevant tracks from Paul Atkinson's HRP Pocket Guide. I've highlighted some tracks in red based on his suggestions for what would constitute his 'ideal' HRP hike, but remember that any large changes in your route will likely influence your resupplies.
See the resupply spreadsheet for details. Distances are reasonable, but remember that you'll be moving much slower here than in the previous section. The stretch leaving Gavernie (France) has the potential to become a very long food carry if the next two stops are closed (this was the case in 2019 but I think I was just incredibly unlucky – Candanchu was closed for renovations and the Lescun shop owners were away on vacation). It's still true that October is the off-season in the Pyrenees and some services may be unavailable, so call ahead to confirm if possible.
Threaded fuel canisters can be found in larger towns in the Pyrenees - certainly in Arinsal (Andorra), but I haven't been able to confirm elsewhere.
Plentiful. Between the fountains in villages and mountain streams you shouldn't have any problems. As always, pay attention to the terrain and fill up if there's a long ridge walk ahead.
Huts / Shelters
With careful planning you could hike the GR10, GR11, or HRP without carrying a shelter. There are many mountain huts along the way - some of which will give discounted stays to those with Alpine Club memberships. Some huts will close for the season during October but most will still have a winter room available. There are also many unstaffed shelters in the mountains which will be a welcome retreat as you face cold fall rain or early snow.
Similar to the last section, if you plan to stay at a campground it will be wise to bring your own soap.
Borders / Transportation / Other
Early in the section there are two areas which prohibit all wild camping. You'll travel through Mantet Nature Preserve for ~16km and then shortly after through Vall d'Eina Nature Preserve for ~8km. A bivouac is permitted along the rest of the suggested route.
Next Section: The Cantabrian Mountains