the wetter Pleistocene climate. Darwin Falls, on the western edge of Death Valley Monument, falls into a large pond surrounded by willows and cottonwood trees. Over 80 species of birds have been recorded around the pond. Efflorescence, also known as salt flowers, is a rare occurrence in Death Valley that occurs when rain soaks into the soil and dissolves salt beneath the surface causing the ground to appear as if there is a light dusting of snow. History Death Valley is home to the Timbisha tribe of Native Americans, formerly known as the Panamint Shoshone, who have inhabited the valley for at least the past millennium. The Timbisha name for the valley, tümpisa, means "rock paint" and refers to the red ocher paint that can be made from a type of clay found in the valley. Some families still live in the valley at Furnace Creek. Another village was in Grapevine Canyon near the present site of Scotty's Castle. It was called maahunu in the Timbisha language, whose meaning is uncertain, although it is known that hunu means 'canyon'. The valley received its English name in 1849 during the California Gold Rush. It was called Death Valley by prospectors and others who sought to cross the valley on their way to the gold fields, after 13 pioneers perished from one early expedition of wagon trains. During the 1850s, gold and silver were extracted in the valley. In the 1880s, borax was discovered and extracted by mule-drawn wagons. Death Valley National Monument was proclaimed on February 11, 1933, by President Herbert Hoover, placing the area under federal protection. In 1994, the monument was redesignated as Death Valley National Park, as well as being substantially expanded to include Saline and Eureka Valleys. Notable attractions and locations Badwater Basin China Ranch Dante's View Darwin Falls Devils Hole Father Crowley Viewpoint Furnace Creek Harmony Borax Works Hells Gate Myers Ranch Oasis at Death Valley Russell Camp New Ryan Upper and Lower Noonday Camp Racetrack Playa, a large dry lakebed within the Valley Sailing stones, famous moving stones of Death Valley Scotty's Castle Shoreline Butte Stovepipe Wells Tecopa Tecopa Hot Springs West Side Borax Camp Wilson Ranch Wildrose Ranger Station Zabriskie Point In popular culture Films A number of movies have been filmed in Death Valley, including: Chimmie Fadden Out West (1915) The Dawn of Understanding (1918) Greed (1924) The Air Mail (1925) The Brute