The Great Basin was formed by tectonic plate movement and faulting through extensional tectonics.

The Great Basin was primarily shaped by tectonic plate movement and faulting. Over millions of years, the region underwent extensional tectonics, where the Earth's crust stretched and fractured along faults, causing large sections of land to sink, forming the basin. Meanwhile, surrounding mountain ranges were uplifted. The distinctive basin-and-range geography, which consists of a succession of alternating mountain ranges and valleys, was produced by this tectonic action. Faulting and tectonic movement are the main geological processes that led to the development of the Great Basin, however other processes like glaciers and volcanic eruptions also played a role.