The Death Valley (plural: valleys of death) Death, or a location or time when death is imminent. (idiomatic) A dangerous location. (noun) The Death Valley is a large arid desert located in California. It is part of the Great Basin. It was named by Spanish explorers after the Tuolumne River which flows through it. They called the area el valle de la muerte (the valley of death). Today, this name is used to describe any place where there is a high risk of death or serious injury. The term death valley has also been used with other locations including Death Valley National Park and Death Valley National Monument. These areas are important for their archaeological resources but also pose some danger because of shifting ground conditions that can lead to rock falls. Death Valley has a thin veneer of sand over hardpan clay, making it susceptible to heat and wind. Summer temperatures in Death Valley can reach up to 120 degrees Fahrenheit (49.4 degrees Celsius), while winter temperatures can drop below 0 degrees F (–18 degrees C). Rainfall is scarce, but when it does fall it tends to be in sudden bursts.