The Great Basin is known for its endorheic or closed basin, where water does not drain into the ocean but instead evaporates or seeps into the ground.

One of the defining features of the Great Basin is its endorheic drainage system, meaning that rivers and streams in the region do not flow to the sea. Instead, they drain into closed basins, where the water either evaporates or infiltrates into the ground. This leads to a lack of outflow to the ocean, which distinguishes it from other major drainage systems. This confined drainage pattern shapes the Great Basin's hydrology and geography, which helps to explain its arid and semi-arid climate.