Which lake is the deepest in South America?

Lake O’Higgins is the deepest lake in South America.

Known as Lake O’Higgins in Chile and Lake San Martín in Argentina, this Patagonian lake reaches a maximum measured depth of 836 metres near the O’Higgins Glacier. That makes it the deepest lake in the Americas by maximum depth and one of the deepest lakes on Earth.

The lake lies across the Chile–Argentina border and has a distinctive, irregular shape made up of several long, finger-like arms. Glacial rock flour suspended in the water gives it a striking milky blue appearance. The O’Higgins and Chico glaciers feed its waters, while the Pascua River carries the outflow westward toward the Pacific Ocean.

The two names honor Bernardo O’Higgins, a Chilean independence leader, and José de San Martín, an Argentine military leader who helped liberate South America. A frequent confusion is Lake Titicaca, which is South America’s highest navigable lake, not its deepest. Lake Maracaibo is much larger in surface area but is relatively shallow, while Lake Buenos Aires is also shared by Chile and Argentina but does not reach the same depth.