Skäckerfjällen literally means The Skäcker mountains and the large nature reserve covers this whole range, which is part of the Scandinavian Mountains. The highest peak is Sandfjället with an altitude of . It is a mountain landscape of a kind typical for the Scandinavian mountain range. Within the area, three old-growth forests exist which are rather different from each other. In the Strådalen area close to the border with Norway, the old-growth forest is dominated by large spruce trees, while in the area around Lake Lågsjön the forest is dominated by Scots pine, often in the form of krummholz. In Rutsdalen area, old-growth forest dominated by spruce is separated from mixed coniferous old-growth forest which grow on thin moraine.