Lake, Yellowstone National Park , northwestern Wyoming, U.S. It lies at 7,731 ft (2,356 m) above sea level, the largest body of water in North America at so high an altitude.
It is fed and drained by the Yellowstone River . About 20 mi (32 km) long and 14 mi (23 km) wide, it has a maximum depth of 390 ft (119 m) and a surface area of 137 sq mi (354 sq km). It is a haven for rare species of waterbirds, including trumpeter swan s, and is prized for trout fishing.