The Sierra Nevada mountain range forms the western edge of the Great Basin.

The Sierra Nevada is a major mountain range that runs along the western edge of the Great Basin, primarily in California and Nevada. It acts as a natural barrier, separating the Great Basin from the Pacific coastal region. The range is known for its high peaks, such as Mount Whitney, and is important for the region's climate, as it influences precipitation patterns. The Great Basin, a sizable, arid region east of the Sierra Nevada, is distinguished by its endorheic (closed) drainage system, which prevents its water from flowing to the ocean.