The Great Basin is a vast area of interior drainage including much of the expanse between the Sierra Nevada and Rocky Mountains. The unique geomorphology of this region has resulted in high local and regional biodiversity. Today, the Great Basin is considered one of the most threatened bioregions in North America. In this Special Feature, we bring together a broad range of perspectives that highlight how Great Basin landscape dynamics from 30 million years ago to today, including modern anthropogenic impacts, have shaped mammalian diversity from individual populations and species to entire biomes.