The Great Basin is the largest area of contiguous endorheic 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 term "Great Basin" is applied to hydrographic,:11 biological, floristic,:21 physiographic,:14 topographic, and ethnographic geographic areas.:34 The name was originally coined by John C. Frémont, who, based on information gleaned from Joseph R. Walker as well as his own travels, recognized the hydrographic nature of the landform as "having no connection to the ocean".:8–9 The hydrographic definition is the most commonly used, and is the only one with a definitive border. The other definitions yield not only different geographical boundaries of "Great Basin" regions, but regional borders that vary from source to source.:11 The Great Basin Desert is defined by plant and animal communities, and, according to the National Park Service, its boundaries approximate the hydrographic Great Basin, but exclude the southern "panhandle".