Death Valley Earth at 134 °F (56.7 °C) on July 10, 1913, as well as the highest recorded natural ground surface temperature on Earth at 201 °F (93.9 °C) on July 15, 1972. Located near the border of California and Nevada, in the Great Basin, east of the Sierra Nevada mountains, Death Valley constitutes much of Death Valley National Park and is the principal feature of the Mojave and Colorado Deserts Biosphere Reserve. It is located mostly in Inyo County, California. It runs from north to south between the Amargosa Range on the east and the Panamint Range on the west; the
Death Valley basins down the Owens River Valley through Searles and China Lakes and the Panamint Valley to the immediate west. As the area turned to desert, the water evaporated, leaving the abundance of evaporitic salts such as common sodium salts and borax, which were later exploited during the modern history of the region, primarily 1883 to 1907. Death Valley has a subtropical, hot desert climate (Köppen: "BWh"), with long, extremely hot summers and short, mild winters, as well as little rainfall. As a general rule, lower altitudes tend to have higher temperatures. When the sun heats the ground, that heat is