This dissertation discusses the evolution of mountains, particularly the interaction between uplift, which is controlled by horizontally-directed plate tectonic and vertically directed isostatic forces, and erosion, which encompasses glacial, periglacial, fluvial and hillslope processes.Rapid rockfall erosion rates in high mountains create extensive talus slopes. Parts of the Southern Alps, New Zealand, are dominated by kilometer-scale scree-mantled slopes which reduce hillslope gradients and decrease drainage densities. Field and aerial photograph-based analysis of scree slopes (i.e. rockfall deposits) reveal a peak in the areal extent and rate of scree slope formation in the eastern Southern Alps.