While the Rockies contain various rock types, granite is a prevalent component, especially in the core of the mountains.

The Rocky Mountains are composed of a variety of rock types due to their complex geological history. However, granite is a significant component, particularly in the older core of the mountain range. This igneous rock, formed from cooled magma deep beneath the Earth's surface, is exposed in many areas due to uplift and erosion. Other rock types present include sedimentary rocks like limestone and sandstone, and metamorphic rocks like gneiss and schist, but granite is a dominant feature.