The department of the Haute-Loire is entirely included in the Massif Central and the catchment areas of the the Loire and Allier in their upper part (without going up until their sources which is respectively in Ardeche with the foot of famous Mont Gerbier de Jonc, and Lozere with the foot of Moure of Gardille).

These high basins are made up:

• of small alluvial plains (Limagne close to Brioude, Emblavez close to the Lavoûte-on-Loire…)
• of wild throats (To combine upstream of Langeac, the Loire and Arzon close to Vorey, Lignon…)
• of hills and solid masses with dominant forest (Livradois towards Chair-God, Margeride towards Saugues, Boutières)
• of plates and volcanic chains (Mounts of Velay, where in altitude the lens is cultivated, pastoral Mézenc, forest Meygal).

The culminating point is the Mont Mézenc (1753 m), from where per good weather the chain of the the Alps realizes.