The variety of mountain ranges makes skiing in Isère so rich. Limestone or crystalline summits, mid-mountain forests and clearings, high altitude peaks and glaciers form a snowy playground from November to June, on the outskirts of Grenoble. This book describes 500 ski touring routes in Isère, classic or new, of all difficulties. To better orient yourself within such diversity, 140 routes selected according to their beauty, their location and their snow cover, and all traveled by the authors, are presented in detail. 360 other routes are described more briefly. This work - it is the fourth revised edition - therefore constitutes a complete inventory (excluding extreme skiing) of the ski touring possibilities in Isère, from easy and short runs to steep slope skiing.