As Lake Manly evaporated to the surface of Death Valley, it left a remarkable legacy. Under the surface of Death Valley is one of the world's largest aquifers. Being fed by the Amargosa River and Salt Creek, this aquifer is barely visible above ground at Badwater Basin, the lowest point in the valley at -282 ft (−86.0 m).
Shoreline Butte has easy-to-see strandlines formed by wave action from the ancient. These features were created by stands of the lake, which would change its depth over time and also cause slight changes in climate. The conditions under which this lake existed are called "pluvial" by geologists instead of glacial because glaciers did not directly touch Death Valley - but the meltwater from the glaciers and the cooler and wetter climate of the time affected the valley. Approximately 8,000 ft (2,400 m) of gravel, sand, and mud overlay the bedrock of the valley floor.
Lake Manly is named after William L. Manly, who was among the original Death Valley party in 1849. Manly and a companion hiked out of Death Valley into the Greater Los Angeles Area, where he found help and returned to rescue his party.
In 2005, severe flooding resulted in Lake Manly reappearing on a large scale. More than 100 square miles (260 km2) were covered by the lake, allowing some tourists and park rangers to become probably the only humans to canoe across Death Valley. The lake was about two feet at its deepest point. It evaporated quickly, leaving behind a mud-salt mixture.