The occupation of the Alps of western Switzerland from the Mesolithic to the end of the Iron Age. - This article deals with the evolution of the distribution in altitude of remains from the Mesolithic to the Iron Age. The territory includes the mountainous part of southwestern Switzerland: Valais, alpine and pre-alpine regions of Berne, Fribourg and Vaud. Four categories of remains can be distinguished: settlements, tombs, deposits and cultural areas, and isolated artefacts. The territory of middle altitude (between 900 and 1700 mast) begins to be discreetly occupied during the Bronze Age. However, this alpine conquest fully asserts itself only during the Iron Age, once adequate control of the different altitudinal zones and high mountain passes was possible.