Exhumation of the granodiorite body probably occurred mostly by erosion of overlying rocks over tens of millions of years, with glacial erosion processes dominating exhumation over the last 2.5 million years. Once exposed at the surface, the original granodiorite body was shaped by glacial erosion, which is responsible for the tall steep walls that define the Chief, as well as the excavation of Howe Sound, a fjord. Classic hallmarks of glacial erosion are ubiquitous, especially polished, striated surfaces. Polish and striations observable at the very summit of the formation require that, at the peak of glaciation, the entire formation was buried under a substantial thickness of ice.