[1] The valley lies between the Kamnik–Savinja Alps to the west, the Pohorje Mountain Range to the east, and the Sava Hills to the south.
The highest peaks rise beyond these: Mount St. Ursula (Uršlja gora, 1,699 m; also named Plešivec), and Smrekovec (1,577 m).
The southern edge along the Ložnica Hills arose along the geologically important Šoštanj Fault, allowing the valley road access towards the east.
The Šalek Valley formed in the late Cenozoic era, during the Pliocene epoch of the Neogene period.
Faults started to appear at this time due to epeirogenic movement, vertically lifting and lowering the surface.