Lake Manly was a pluvial, former freshwater, endorheic, rift lake that filled the Death Valley basin of Inyo County, California through the Holocene before the area's climate changed to desert. Following its isolation from the Colorado River system, Lake Manly receded by evaporation with Badwater Basin, Middle Basin, and Cotton Ball Marsh occupying the space left behind. At its greatest extent Lake Manly was roughly 80 mi (130 km) long and 600 ft (180 m) deep.