The Reserve includes the highest mountain in Canada, Mount Logan () of the Saint Elias Mountains. Mountains and glaciers dominate the park's landscape, covering 83% of its area. The rest of the land in the park is forest and tundra—east of the largest mountains and glaciers—where the climate is colder and drier than in the western and southern parts of the park. Trees grow only at the park's lowest elevations. The primary tree species are white spruce, balsam poplar and trembling aspen.