The Great Basin is the largest area of contiguousendorheic watersheds in North America. It is noted for both its arid climate and the 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.

The Great Basin includes valleys, basins, lakes and mountain ranges of Basin and Range topography, with some in the phytogeographicBasin and Range Province.[3] 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.

Ecology

Although mostly within the North American Desertecoregion, portions of the Great Basin extend into the Forested Mountain and Mediterranean Californiaecoregions. The semi-arid areas of the Forested Mountain ecoregion include the White Mountains and Inyo Mountains.[citation needed] Extending north of the 42nd parallel north, the Northern Basin and Range (ecoregion) has its southern border at the highest shoreline of the PleistoceneLake Bonneville. The south edge of the Central Basin and Range ecoregion is in Nevada, north of the south edge of the Great Basin section.

In phytogeography, the Great Basin is within the Great Basin (floristic) Province of the Madrean Region in southwestern North America. The floristic province and region are within the Holarctic Kingdom, of the northern Western Hemisphere..