 The mountain consists of four overlapping dormant volcanic cones that have built a complex shape, including the main summit and the prominent satellite cone of Shastina, which has a visibly conical form.If Shastina were a separate mountain, it would rank as the fourth-highest peak of the Cascade Range (after Mount Rainier, Rainier's Liberty Cap, and Mount Shasta itself).Mount Shasta's surface is relatively free of deep glacial erosion except, paradoxically, for its south side where Sargents Ridge runs parallel to the U-shaped Avalanche Gulch.