The Great Basin is the largest area of contiguous endorheic watersheds in North America. It is noted for both its arid conditions and its Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than 100 miles (160 km) away at the summit of Mount Whitney. The region spans several physiographic divisions, biomes/ecoregions, and deserts, and is the ancestral homeland of the Great Basin tribes.

The Great Basin includes valleys, basins, lakes, and mountain ranges of Basin and Range topography. The Great Basin almost entirely contains the smaller Great Basin physiographic section, which extends about 10,000 sq mi (26,000 km²) into the Colorado River watershed (including the Las Vegas metropolitan area and northwest corner of Arizona). Geographic features near the Great Basin include the Continental Divide of the Americas, the Great Divide Basin, and the Gulf of California.

The Great Basin's two most populous metropolitan areas are Reno to the west and Salt Lake City on the east side. The area between these two cities is sparsely populated, but includes the smaller cities of Delta, Elko, Ely, Tonopah, Wendover, West Wendover, and Winnemucca. The southern area of the basin has the communities of Palmdale, Victorville, and Palm Springs. Major roadways traversing the Great Basin include Interstate 80, Interstate 15, U.S. Route 6, U.S. Route 50, U.S. Route 93, U.S. Route 95 and U.S. Route 395, with the Nevada section of U.S. Route 50 nicknamed "The Loneliest Road in America".Union Pacific's Overland Route also passes through Reno and Salt Lake City.^{[dubious – discuss]}