Lake Tear of the Clouds () is a small tarn, in Essex County, New York, on the southwest slope of Mount Marcy; it is both the highest lake in the state and the highest source of the Hudson River via Feldspar Brook and the Opalescent River. The Hudson River officially begins several miles southwest of Marcy at Henderson Lake (1,814 ft).

The lake was discovered in 1872, by Verplanck Colvin while he was surveying the Adirondacks. He wrote:

On September 14, 1901, then-Vice President Theodore Roosevelt was at Lake Tear of the Clouds after returning from a hike to the Marcy summit when he received a message informing him that President William McKinley, who had been shot two weeks earlier but expected to survive, had taken a turn for the worse.

Roosevelt hiked down 10 miles (16 km) on the southwest side of the mountain to the closest stage station at Newcomb, New York. He then took a midnight stagecoach ride on twisting roads to the Adirondack Railway station at North Creek, New York where he learned that McKinley had died. Roosevelt took the train to Buffalo where he was officially sworn in as President.

The 40-mile (64 km) route is now designated the Roosevelt-Marcy Trail.