The Cantabrian Mountains
Section 7 of the Trans-European Alpine Route
The westernmost section of the TEAR traverses the Cantabrian Mountains before making a final push to the Atlantic along the ancient pilgrimage routes to Santiego de Compostela.
Many people will think of warm and sunny days when imagining a trek across Spain, but this is green Spain and rain will become more and more frequent as you near Europe's western edge and the end of the TEAR.
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.
The main route follows a lengthy combination of Spanish GR routes until reaching Oviedo, where the Camino Primitivo (Primitive Way) begins. The GR trails are not consistently maintained. Some are are clear and well signed while others have been neglected. There will be mud and gorse, but there will also be beauty. Picos de Europa National Park, at roughly the halfway point, is a highlight. Shortly afterwards, the TEAR joins the Camino Primitivo, the oldest of the Caminos to Santiego de Compostela. Although it has the least road walking of all Caminos, it's not a wilderness path by any means. Navigation is easy and the terrain is fast, so you'll soon reach Santiego de Compostela where you can pick your Compostela before continuing towards the Atlantic on the Camino Finisterre. There are offline navigation apps for the main Caminos which I highly recommend downloading.
There aren't many minor alternates along the main route, but there are several major ones which alter the entire trajectory of this section. If you choose to extend your traverse of the Pyrenees all the way to the ocean (using the GR11/HRP), you could then follow the Camino Norte along the north coast to Santiego de Compostela. Temperatures will be more moderate and overall the path is shorter, although you will be signing up for much more paved road walking and will bypass Picos de Europa National Park as well as the rest of the Cantabrian Mountains. A possible compromise might be to walk the Camino Norte until reaching the Camino Lebaniego, which heads south and intersects the main route just as it enters Picos de Europa.
See the resupply spreadsheet for details. There's a 177km stretch between Izarra and Barcena de Pie de Concha, but all other resupplies are shorter than 100km.
Threaded fuel canisters can be found in a few of the larger towns and cities (Pamplona, Potes, and Oviedo at minimum).
Other than atop prolonged ridges there will likely be plenty of water sources.
Huts / Shelters
Few along the GR paths, but along any of the Caminos there are albergues (hostels) every night. As long as you have a pilgrim's Credencial you can stay at the municipal albergues for 5-8EU per night. Private albergues are slightly more expensive but often have nicer facilities.
Again, campgrounds may not provide any soap.
Borders / Transportation / Other
Buses run daily between Fisterra and Santiago de Compostela. Details can be found at the Fisterra municipal albergue, and the bus stop is out front.