Download coordinates as: The Great Basin Divide in the western United States is the ridgeline that separates the Great Basin from the Pacific Ocean watershed, which completely surrounds it.

The Great Basin is the largest set of contiguous endorheic watersheds of North America, including six entire USGS watershed subregions.

As such, it occupies most of present-day Nevada, about half of Utah, large parts of eastern California and Oregon, and small parts of Idaho, Wyoming, and Baja California.

The arid climate of this area ensures that none of the major lake basins are filled to overflowing, and thus no precipitation falling into them reaches the sea.

Precipitation falling on the exterior of the Great Basin Divide does (if not evaporated or consumed on the way) reach the Pacific Ocean, through a number of different channels.