 The range started to uplift four million years ago, and erosion by glaciers exposed the granite and formed the light-colored mountains and cliffs that make up the range.The uplift caused a wide range of elevations and climates in the Sierra Nevada, which are reflected by the presence of five life zones (areas with similar plant and animal communities).Uplift continues due to faulting caused by tectonic forces, creating spectacular fault block escarpments along the eastern edge of the southern Sierra.